Open-type earphones

Abstract

The open-type earphone according to an embodiment of the present application includes an acoustic generating unit including a transducer including a diaphragm and a housing that accommodates the transducer, and an ear hook that, when worn, has a first portion that is hung between the user's auricle and head and a second portion that extends to the side of the auricle away from the head and is connected to the acoustic generating unit, and fixes the acoustic generating unit at a position near the auditory canal so as not to block the auditory canal, and a sound emission hole is formed on the inner surface of the housing facing the auricle, which guides sound generated in front of the diaphragm out of the housing and transmits it to the auditory canal, and at least two decompression holes are formed on another side wall of the housing, and the at least two decompression holes include a first decompression hole and a second decompression hole, and the distance between the center of the first decompression hole and the center of the second decompression hole is 13.0 mm to 15.2 mm.

Description

Technical Field

[0001] This application relates to the field of acoustics, and particularly to open-type earphones.

[0002] [Incorporation by Reference] This application claims the priority of a Chinese application with application number 202211336918.4 filed on October 28, 2022, the priority of a Chinese application with application number 202223239628.6 filed on December 1, 2022, and the priority of an international application with application number PCT / CN2022 / 144339 filed on December 30, 2022. All of its contents are incorporated herein by reference.

Background Art

[0003] With the development of acoustic output technology, acoustic devices (such as earphones) are widely applied in people's daily lives. By using them together with electronic devices such as mobile phones and computers, users can enjoy an auditory feast. An open-type earphone is a portable audio output device that realizes acoustic conduction within a specific range. Compared with conventional canal-type earphones and headphones, open-type earphones have the characteristics of not blocking or covering the ear canal, so that users can obtain voice information in the external environment while listening to music, thus improving safety and comfort. The output performance of open-type earphones has a great impact on the user's comfort in use.

[0004] Therefore, there is a need to provide an open-type earphone that improves the output performance of open-type earphones.

Summary of the Invention

Means for Solving the Problems

[0005] The open-type earphone according to an embodiment of the present application includes an acoustic generating unit including a transducer including a diaphragm and a housing for housing the transducer, and in a wearing state, a first portion is hung between the user's auricle and the head, and a second portion extends to a side away from the head of the auricle and is connected to the acoustic generating unit, fixing the acoustic generating unit to a position near the ear canal so as not to block the ear canal, and an ear hook, and on an inner surface of the housing facing the auricle, a sound emitting hole for guiding the sound generated on the front side of the diaphragm out of the housing and transmitting it to the ear canal is formed, and on another side wall of the housing, at least two decompression holes are formed, the at least two decompression holes include a first decompression hole and a second decompression hole, and the distance between the center of the first decompression hole and the center of the second decompression hole is 13.0 mm to 15.2 mm.

[0006] In some embodiments, the distance from the center of the sound emitting hole to the perpendicular bisecting plane of the connection line between the center of the first decompression hole and the center of the second decompression hole is 0 mm to 2 mm.

[0007] In some embodiments, the first decompression hole is formed on the upper surface of the housing, and the second decompression hole is formed on the lower surface of the housing.

[0008] [[ID=1十二]]In some embodiments, in a wearing state, the housing is at least partially inserted into the concha cavity, and the distance from the center of the second decompression hole to the rear surface of the housing is greater than the distance from the center of the first decompression hole to the rear surface.

[0009] In some embodiments, the range of the distance from the center of the first decompression hole to the inner surface of the housing facing the auricle is 4.24 mm to 6.38 mm.

[0010] In some embodiments, the range of the distance from the center of the first decompression hole to the rear surface is 10.44 mm to 15.68 mm.

[0011] In some embodiments, the transducer includes a magnetic circuit assembly for providing a magnetic field, and the range of the distance from the center of the first decompression hole to the bottom surface of the magnetic circuit assembly is 1.31 mm to 1.98 mm.

[0012] In some embodiments, the transducer includes a magnetic circuit assembly that provides a magnetic field, and the distance from the center of the first depressurization hole to the major axis center plane of the magnetic circuit assembly is in the range of 5.45 mm to 8.19 mm.

[0013] In some embodiments, the distance from the center of the second decompression hole to the inner surface of the housing toward the auricle is in the range of 4.24 mm to 6.36 mm. In some embodiments, the distance from the center of the second decompression hole to the rear surface is in the range of 13.51 mm to 20.27 mm.

[0014] In some embodiments, the transducer includes a magnetic circuit assembly that provides a magnetic field, and the distance from the center of the second depressurization hole to the bottom surface of the magnetic circuit assembly ranges from 1.31 mm to 1.98 mm.

[0015] In some embodiments, the transducer includes a magnetic circuit assembly that provides a magnetic field, and the distance from the center of the second depressurization hole to the major axis center plane of the magnetic circuit assembly ranges from 5.46 mm to 8.20 mm.

[0016] In some embodiments, when worn, the housing is inserted at least partially into the concha, and the area of ​​the second decompression port is smaller than the area of ​​the first decompression port.

[0017] In some embodiments, the area range of the first decompression hole is 3.78 mm 2 ~22.07mm 2 The area of ​​the second decompression port is 2.78 mm². 2 ~16.07mm 2 That is the case.

[0018] In some embodiments, the ratio of the area of ​​the first decompression hole to the area of ​​the upper surface is 0.036 to 0.093, and the ratio of the area of ​​the second decompression hole to the area of ​​the lower surface is 0.018 to 0.051.

[0019] In some embodiments, the transducer includes a magnetic circuit assembly that provides a magnetic field, and the overlapping area of ​​the projections of the first and second decompression holes on the longitudinal central plane of the magnetic circuit assembly is 10.77 mm². 2 The following applies:

[0020] In some embodiments, the range of the length of the connection line between the projection points of the centers of the first and second pressure relief holes in the plane on which the bottom surface of the magnetic circuit assembly is located is 8.51 mm to 15.81 mm.

[0021] In some embodiments, the angular range of the angle between the connecting wire and the short axis of the housing is 12.85° to 23.88°.

[0022] In some embodiments, when worn, the housing covers the antihelix at least partially, and the difference between the distance from the center of the second decompression hole on the lower side to the posterior side of the housing and the distance from the center of the first decompression hole on the upper side to the posterior side is less than 10%.

[0023] In some embodiments, the distance from the center of the first decompression hole to the inner surface of the housing toward the auricle is in the range of 4.43 mm to 7.96 mm, or the distance from the center of the second decompression hole to the inner surface is in the range of 4.43 mm to 7.96 mm.

[0024] In some embodiments, the distance from the center of the first decompression hole to the rear side is in the range of 8.60 mm to 12.92 mm, or the distance from the center of the second decompression hole to the rear side is in the range of 8.60 mm to 12.92 mm.

[0025] In some embodiments, the ratio of the major axis dimension of the first depressurization port to the minor axis dimension of the first depressurization port is in the range of 1 to 8, or the ratio of the major axis dimension of the second depressurization port to the minor axis dimension of the second depressurization port is in the range of 1 to 8.

[0026] In some embodiments, there is a first distance between the center of the first decompression port and the center of the sound emission port, and a second distance between the center of the second decompression port and the sound emission port, with the difference between the first distance and the second distance being less than 10%.

[0027] In some embodiments, the first distance is between 5.12 mm and 15.11 mm.

[0028] In some embodiments, the distance from the projection point of the center of the first decompression hole onto the sagittal plane to the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane is 2 mm or less.

[0029] In some embodiments, the distance from the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane to the projection point of the center of the ear canal opening onto the sagittal plane is in the range of 12 mm to 18 mm.

[0030] In some embodiments, the distance from the projection point of the center of the first decompression hole onto the sagittal plane to the projection point of the center of the ear canal onto the sagittal plane is in the range of 12 mm to 18 mm.

[0031] In some embodiments, the distance from the projection point of the center of the second decompression hole onto the sagittal plane to the projection point of the center of the ear canal onto the sagittal plane is in the range of 6.88 mm to 10.32 mm.

[0032] In some embodiments, the distance from the projection point of the center of the second decompression hole onto the sagittal plane to the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane is in the range of 14.4 mm to 21.6 mm.

[0033] In some embodiments, the distance range from the projection point of the center of the first decompression hole onto the sagittal plane to the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane is 13.76 mm to 20.64 mm.

[0034] In some embodiments, the distance range from the projection point of the center of the second decompression hole onto the sagittal plane to the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane is 8.16 mm to 12.24 mm.

[0035] In some embodiments, the distance range from the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane to the projection point of the center of the ear canal onto the sagittal plane is 1.76 mm to 2.64 mm.

[0036] In some embodiments, when worn, the distance in the longitudinal axis direction between the first decompression hole and any point on the second part of the ear hook from the sound generating part is in the range of 5.28 mm to 13.02 mm.

[0037] An open-type earphone according to an embodiment of this specification includes an acoustic generating unit including a transducer with a diaphragm and a housing that houses the transducer, and an ear hook that, when worn, has a first portion that is placed between the user's auricle and head, and a second portion that extends to the side of the auricle away from the head and is connected to the acoustic generating unit, thereby fixing the acoustic generating unit in a position near the ear canal so as not to block the ear canal, wherein a sound emission hole is formed on the inner surface of the housing facing the auricle to guide sound generated on the front side of the diaphragm out of the housing and transmit it to the ear canal, and at least two decompression holes are formed on the other side wall of the housing, the at least two decompression holes including a first decompression hole and a second decompression hole, and the distance from the center of the sound emission hole to the perpendicular bisector plane of the connecting line between the center of the first decompression hole and the center of the second decompression hole is 0 mm to 2 mm.

[0038] An open-type earphone according to an embodiment of this specification includes an acoustic generating unit including a transducer with a diaphragm and a housing for housing the transducer, and an ear hook that, when worn, has a first portion that is placed between the user's auricle and head and a second portion that extends to the side of the auricle away from the head and is connected to the acoustic generating unit, thereby fixing the acoustic generating unit in a position near the ear canal so as not to block the ear canal, wherein a sound discharge hole is formed on the inner surface of the housing facing the auricle to guide sound generated on the front side of the diaphragm out of the housing and transmit it to the ear canal, and at least two decompression holes are formed on the other side wall of the housing, the at least two decompression holes including a first decompression hole and a second decompression hole, the housing is at least partially inserted into the concha, and the area of ​​the second decompression hole is smaller than the area of ​​the first decompression hole.

[0039] The present application will be further described by exemplary embodiments, which will be described in detail with reference to the drawings. These embodiments are not limiting, and in these embodiments, the same reference numerals indicate the same structure. [Brief explanation of the drawing]

[0040] [Figure 1] This is a schematic diagram illustrating an exemplary ear portion according to several embodiments of the present application. [Figure 2] This is an illustrative diagram of an open-type earphone according to some embodiments of the present invention. [Figure 3] These are schematic diagrams of two point sound sources and listening positions according to some embodiments of the present application. [Figure 4] This is a comparative diagram of the sound leakage index at different frequencies for a single-point source and a dual-point source according to several embodiments of the present application. [Figure 5] This is a schematic diagram illustrating an exemplary distribution in which a baffle is placed between two sound sources of a dipole sound source according to some embodiments of the present application. [Figure 6] This figure shows the sound leakage index for several embodiments of the present invention, with and without a baffle installed between the two sound sources of a dipole sound source. [Figure 7] This is a schematic diagram illustrating the exemplary mounting of open-type earphones according to several embodiments of the present invention. [Figure 8] Figure 7 is a schematic diagram of the ear-facing side of an open-type earphone. [Figure 9] Figure 8 is a schematic diagram of the housing configuration. [Figure 10] This is a schematic diagram illustrating an exemplary distribution in which a cavity structure is installed around one of the dipole sound sources according to some embodiments of the present application. [Figure 11A] This is a schematic diagram of the listening principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources, according to some embodiments of the present application. [Figure 11B]This is a schematic diagram illustrating the principle of sound leakage in a case where a cavity structure is constructed around one of the dipole sound sources, according to some embodiments of the present application. [Figure 12A] This is a schematic diagram of a cavity structure having two horizontal openings according to some embodiments of the present application. [Figure 12B] This is a schematic diagram of a cavity structure having two vertical openings according to some embodiments of the present application. [Figure 13] This is a comparative diagram of the listening exponential curves of a cavity structure having two openings and a cavity structure having one opening, according to some embodiments of the present application. [Figure 14] This is a schematic diagram illustrating the exemplary mounting of open-type earphones according to some other embodiments of the present invention. [Figure 15] Figure 14 is a schematic diagram of the ear-facing side of an open-type earphone. [Figure 16] This is a schematic diagram of the housing of an open-type earphone according to some embodiments of the present invention. [Figure 17] These are frequency response curve diagrams of open-type earphones corresponding to first pressure-reducing holes of different areas according to some embodiments of the present application. [Figure 18] This is a frequency response curve diagram of an open-type earphone corresponding to a second pressure-reducing hole of a different area, according to some embodiments of the present application. [Figure 19] This is a schematic projection onto the sagittal plane of an open-type earphone according to several embodiments of the present application when it is being worn. [Figure 20A] This is an illustrative internal configuration diagram of an acoustic generating unit according to several embodiments of the present invention. [Figure 20B] This is an illustrative diagram of a second acoustic cavity according to some embodiments of this specification. [Figure 20C] These are frequency response curve diagrams of rear cavities corresponding to different sizes of included angle α, according to some embodiments of this specification. [Figure 21] This is an illustrative internal diagram of a transducer according to some embodiments of the present application. [Figure 22]This is a schematic diagram of the housing of an open-type earphone, oriented along the Z-direction on the plane where the bottom surface of the magnetic circuit assembly is located. [Modes for carrying out the invention]

[0041] To more clearly illustrate the technical means of the embodiments of this application, the drawings necessary for describing the embodiments are briefly described below. Clearly, the drawings described below are only a few examples or embodiments of this application, and those skilled in the art can apply this application to other similar scenarios based on these drawings without requiring any creative effort. Unless otherwise stated or as is evident from the context, the same numbers in the figures indicate the same structure or operation.

[0042] It should be understood that the terms “system,” “apparatus,” “unit,” and / or “module” as used herein are ways of distinguishing various assemblies, elements, components, parts, or assemblies of different levels. However, other terms may be used in place of the above terms if they can achieve the same purpose.

[0043] As used in this application and claims, unless the context explicitly indicates otherwise, terms such as “one,” “one,” “one kind,” and / or “the” do not specifically mean singular and may include plural forms. Generally, the terms “includes” and “contains” merely indicate the inclusion of clearly identified steps and elements, which are not an exclusive list, and the method or apparatus may include other steps or elements.

[0044] In this description, terms such as "first," "second," "third," and "fourth" are for descriptive purposes only and should not be understood as indicating or suggesting relative importance, or implicitly indicating the quantity of the technical features described. Therefore, features limited by "first," "second," "third," and "fourth" may be explicitly or implicitly indicated to include at least one such feature. In this description, unless otherwise clearly and specifically defined, "plural" means at least two, for example, two, three, etc.

[0045] In this application, unless otherwise explicitly stated and limited, the terms "connection," "fixed," etc., should be understood in a broad sense. For example, unless otherwise explicitly limited, the term "connection" may be a fixed connection, a removable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection via an intermediate medium; or it may be an internal communication between two elements or an interaction relationship between two elements. A person skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific situation.

[0046] Figure 1 is a schematic diagram of an exemplary ear according to several embodiments of the present application. As shown in Figure 1, the ear 100 (also called the auricle) may include the external auditory canal 101, the conchaecular cavity 102, the conchaecular scaphoides 103, the triangular fossa 104, the antihelix 105, the scaphoid fossa 106, the helix 107, the earlobe 108, the tragus 109, and the crura of the helix 1071. In some embodiments, the stability of the attachment of an acoustic device can be achieved by support for the acoustic device by one or more parts of the ear 100. In some embodiments, parts such as the external auditory canal 101, the conchaecular cavity 102, the conchaecular scaphoides 103, and the triangular fossa 104 have a certain depth and volume in three-dimensional space, and can meet the attachment needs of an acoustic device. For example, an acoustic device (e.g., an in-ear earphone) may be attached to the external auditory canal 101. In some embodiments, the attachment of an acoustic device (e.g., an open-type earphone) can be achieved by parts of the ear 100 other than the external auditory canal 101. For example, the acoustic device can be attached to parts such as the conchaepodonium 103, triangular fossa 104, antihelix 105, scaphoid fossa 106, and helix 107, or a combination thereof. In some embodiments, parts such as the user's earlobe 108 may be further utilized to improve the comfort and reliability of the acoustic device. The acoustic device can be attached and sound transmitted through parts of the ear 100 other than the external auditory canal 101, thereby "freeing" the user's external auditory canal 101. When the user is wearing an acoustic device (e.g., open-type earphones), the acoustic device does not block the user's external auditory canal 101 (or ear canal or ear canal opening), allowing the user to hear sounds from the acoustic device as well as sounds from the environment (e.g., car horns, bicycle bells, voices of people around, traffic controllers, etc.), thereby reducing the probability of traffic accidents. In some embodiments, by designing the acoustic device to conform to the structure of the ear portion 100 according to the structure of the ear portion 100, it is possible to attach the sound generating part of the acoustic device to different positions on the ear portion.For example, if the acoustic device is an open-type earphone, the open-type earphone may include a suspension structure (e.g., an ear hook) and an acoustic generating part, and the acoustic generating part and the suspension structure may be physically connected, and the suspension structure may conform to the shape of the auricle such that the whole or a part of the acoustic generating part is positioned on the anterior side of the tragus 109 (e.g., the area J enclosed by the dashed line in Figure 1). Also, for example, if the user is wearing the open-type earphone, the whole or a part of the acoustic generating part may be in contact with the upper part of the external auditory canal 101 (e.g., the location where one or more parts such as the conchaepodum 103, triangular fossa 104, antihelix 105, scaphoid fossa 106, helix 107, and crura of the helix 1071 are located). Furthermore, for example, if the user is wearing open-type earphones, the entire or partial structure of the sound generating unit may be located within a cavity formed by one or more parts of the ear portion 100 (e.g., the conchaecular cavity 102, the conchaecular septum 103, and the triangular fossa 104, etc.) (for example, a region M1 enclosed by the dashed line in Figure 1, including at least the conchaecular septum 103 and the triangular fossa 104, and a region M2 including at least the conchaecular cavity 102).

[0047] Because individual differences may exist among different users, there may be dimensional differences in the shape, size, and other aspects of the ear. For the sake of ease of explanation and understanding, unless otherwise specified, this application will primarily use an ear model having a "standard" shape and dimensions as a reference to further describe the methods of attaching the acoustic device to the ear model in different embodiments. For example, a simulator including a head and its (left and right) ears manufactured according to ANSI:S3.36, S3.25, and IEC:60318-7 standards, such as GRAS 45BC KEMAR, can be used as a reference object for attaching the acoustic device, thereby presenting a scenario in which most users can successfully attach the acoustic device. As merely an example, the reference ear may have the following characteristics: the dimension of the projection of the auricle onto the sagittal plane in the vertical axis direction is in the range of 49.5 mm to 74.3 mm, and the dimension of the projection of the auricle onto the sagittal plane in the sagittal axis direction is in the range of 36.6 mm to 55 mm. Therefore, the descriptions "attached by the user," "in an attached state," and "in an attached state" in this application may refer to the acoustic device described in this application being attached to the ear portion of the simulator. Naturally, considering that there are individual differences among different users, the structure, shape, size, thickness, etc., of one or more parts of the ear portion 100 may have specific differences, and differentiated designs can be made for the acoustic device to meet the needs of different users. These differentiated designs can be expressed to adapt to different ear portions by having characteristic parameters of one or more parts of the acoustic device (for example, the sound generating part, ear hook, etc.) have different ranges of values.

[0048] In fields such as medicine and anatomy, three basic planes of the human body—the sagittal plane, coronal plane, and horizontal plane—and three basic axes—the sagittal axis, coronal axis, and vertical axis—can be defined. The sagittal plane is a cross-section perpendicular to the ground, cut along the anterior-posterior direction of the body, dividing the body into two parts, left and right. The coronal plane is a cross-section perpendicular to the ground, cut along the lateral direction of the body, dividing the body into two parts, anterior and posterior. The horizontal plane is a cross-section parallel to the ground, cut along the vertical direction perpendicular to the body, dividing the body into two parts, upper and lower. Accordingly, the sagittal axis is the axis perpendicular to the coronal plane, running along the anterior-posterior direction of the body; the coronal axis is the axis perpendicular to the sagittal plane, running along the lateral direction of the body; and the vertical axis is the axis perpendicular to the horizontal plane, running along the vertical direction of the body. Furthermore, the term "anterior side of the ear" as used in this application is a concept in contrast to "posterior side of the ear," with the former being the side of the ear away from the head and the latter being the side of the ear facing the head. By viewing the ear of the simulator from the direction in which the coronal axis of the human body is located, a schematic diagram of the anterior contour of the ear shown in Figure 1 can be obtained.

[0049] Figure 2 is an illustrative configuration diagram of an open-type earphone according to some embodiments of the present application.

[0050] In some embodiments, the open-type earphone 10 may include, but is not limited to, air conduction earphones and bone conduction earphones. In some embodiments, the open-type earphone 10 may be combined with products such as glasses, headphones, head-mounted displays, and AR / VR helmets.

[0051] As shown in Figure 2, the open-type earphone 10 may include an acoustic generating unit 11 and an ear hook 12.

[0052] The sound generating unit 11 may be used to be worn on the user's body and can generate sound and input it into the user's ear canal. In some embodiments, the sound generating unit 11 may include a transducer (for example, a transducer 116 shown in Figure 20A) and a housing 111 that houses the transducer. The housing 111 may be connected to an ear hook 12. The transducer is used to generate sound by converting electrical signals into corresponding mechanical vibrations. In some embodiments, a sound vent 112 is formed on the side of the housing facing the auricle and is used to transmit the sound generated by the transducer into the ear canal so that the user can hear the sound after it has been led out of the housing 111. In some embodiments, the transducer (e.g., a diaphragm) may partition the housing 111 to form a front cavity (e.g., a front cavity 114 shown in Figure 20A) and a rear cavity of the earphone, and the sound outlet 112 communicates with the front cavity, allowing sound generated in the front cavity to be guided out of the housing 111 and transmitted to the ear canal. In some embodiments, the sound guided out through the sound outlet 112 can be partially transmitted to the ear canal to allow the user to hear the sound, and the other part, along with the sound reflected in the ear canal, can be transmitted to the outside of the open-type earphone 10 and the ear through the gap between the sound generating part 11 and the ear (e.g., the part of the concha not covered by the sound generating part 11), thereby forming a first sound leakage in the far field, and at the same time, other sides of the housing 111 (e.g., away from or separated from the user's ear canal) Generally, one or more decompression holes 113 are formed on the side, and the decompression holes 113 are further from the ear canal than the sound emission holes 112. The sound propagated from the decompression holes 113 generally forms a second sound leakage in the far field, and when the intensity of the first sound leakage and the intensity of the second sound leakage are equal, and the phases of the first sound leakage and the phases of the second sound leakage are (substantially) out of phase with each other, they can cancel each other out of phase in the far field, which helps to reduce sound leakage in the far field of the open-type earphone 10.In some embodiments, in addition to the side of the housing 111 facing the auricle, at least two depressurization holes 113 may be formed on other sides of the housing 111. By providing at least two depressurization holes 113, not only is the sound generated in the rear cavity drawn out of the housing 111, but the high-pressure region of the sound field in the rear cavity is destroyed, thereby shortening the wavelength of standing waves in the rear cavity and making the resonant frequency of the sound drawn out of the housing 111 from the depressurization holes 113 as high as possible, for example, greater than 4 kHz. In this case, the sound drawn out from the sound emission hole 112 and the sound drawn out from the depressurization holes 113 can maintain a high degree of agreement over a wider frequency range, the effect of interference cancellation between the two in the far field is higher, and thereby a higher sound leakage reduction effect is achieved. For convenience of explanation, this specification illustrates the case in which two depressurization holes are provided in the sound generating unit 11. As a mere example, at least two pressure relief holes 113 may include a first pressure relief hole and a second pressure relief hole (for example, the first pressure relief hole 1131 and the second pressure relief hole 1132 in Figure 7), and the two pressure relief holes 113 may be located on two opposing sides of the housing 111, respectively, to maximize the disruption of the high-pressure region of the sound field in the rear cavity, for example, by being positioned back to each other in the short axis direction Y below. In short, when a user wears the open-type earphone 10, they hear sound transmitted to the ear canal mainly through the sound outlet 112, and the pressure relief holes 113 are mainly installed to balance the pressure in the rear cavity, so that they can vibrate sufficiently at low frequencies and large amplitudes, thereby making the sound sound as bass-extended and clear as possible, and reducing sound leakage into the environment through the sound outlet 112. For more details on the sound generating unit 11, see Figures 7, 14, 20A, etc. and their descriptions, and other parts of this application.

[0053] The ear hook 12 may have one end connected to the sound generating unit 11 and the other end extending along the boundary between the user's ear and head. In some embodiments, the ear hook 12 may have an arc-shaped structure that conforms to the user's auricle so that it is suspended from the user's auricle. For example, the ear hook 12 may have an arc-shaped structure that conforms to the boundary between the user's head and ear so that it is worn between the user's ear and head. In some embodiments, the ear hook 12 may have a clamping structure that conforms to the user's auricle so that it is clamped onto the user's auricle. Exemplarily, the ear hook 12 may include a sequentially connected hook-shaped portion (a first portion 121 shown in Figure 7) and a connecting portion (a second portion 122 shown in Figure 7). The connecting portion connects the hook-shaped portion and the sound generating unit 11 such that the open-type earphone 10 exhibits a curved shape in three-dimensional space when it is not worn (i.e., in its natural state). In other words, in three-dimensional space, the hook-shaped portion, the connecting portion and the sound generating unit 11 are not on the same plane. When installed in this manner, when the open-type earphone 10 is worn, the hook-shaped portion is mainly hooked between the back of the user's ear and the head, and the sound generating portion 11 mainly contacts the front of the user's ear, thereby allowing the sound generating portion 11 and the hook-shaped portion to work together to grip the ear. For example, the connecting portion may extend from the head to the outside of the head and further work together with the hook-shaped portion to provide a pressing force to the sound generating portion 11 toward the front of the ear. The sound generating portion 11 can be pressed against the area where parts such as the concha 102, conchas naviculares 103, triangular fossa 104, and antihelix 105 are located by the action of the pressing force, thereby not blocking the external auditory canal 101 of the ear when the open-type earphone 10 is worn.

[0054] In some embodiments, to improve the stability of the open-type earphone 10 when worn, the open-type earphone 10 may be equipped with one or a combination of the following methods: Firstly, at least a portion of the ear hook 12 is positioned as a mimic structure that fits to the rear of the ear portion 100 and at least one of the head, thereby increasing the contact area between the ear hook 12 and the ear portion 100 and / or the head, and thereby increasing the resistance of the open-type earphone 10 to falling off the ear portion 100. Secondly, at least a portion of the ear hook 12 is positioned as an elastic structure that has a constant amount of deformation when worn, thereby increasing the positive pressure of the ear hook 12 on the ear portion and / or the head, and thereby increasing the resistance of the open-type earphone 10 to falling off the ear portion. Thirdly, at least a portion of the ear hook 12 is positioned to contact the head when worn, generating a reaction force that presses against the ear portion, thereby pressing the sound generating portion 11 to the front of the ear portion, and thereby increasing the resistance of the open-type earphone 10 to falling off the ear portion. Fourth, the sound generating unit 11 and the ear hook 12 are positioned to clamp the area where the antihelix is ​​located, the area where the concha is located, etc., from both the front and rear sides of the ear when worn, thereby increasing resistance to the open-type earphone 10 falling off the ear. Fifth, the sound generating unit 11 or the auxiliary structure connected thereto is positioned to be inserted at least partially into a cavity such as the concha, conchaeoflavone, triangular fossa, and scaphoid fossa, thereby increasing resistance to the open-type earphone 10 falling off the ear.

[0055] In some embodiments, the ear hook 12 may include, but is not limited to, an ear loop, elastic band, etc., to better secure the open-type earphone 10 to the user's body and prevent it from falling out during use. In some embodiments, the open-type earphone 10 may not include the ear hook 12, and the sound generating unit 11 may be fixed near the user's ear 100 by suspension or clamping.

[0056] In some embodiments, the sound generating unit 11 may have a regular or irregular shape, such as an annular, elliptical, racetrack, polygonal, U-shaped, V-shaped, or semicircular, so that it can be directly attached to the user's ear 100. In some embodiments, the sound generating unit 11 may have a major axis X and a minor axis Y perpendicular to each other and perpendicular to the thickness direction Z. The major axis X may be defined as the direction in which the extended dimension is largest in the shape of the two-dimensional projection plane of the sound generating unit 11 (for example, a projection onto the plane on which the outer surface of the sound generating unit 11 is located, or a projection onto the sagittal plane) (for example, if the projection shape is rectangular or approximately rectangular, the major axis is the length direction of the rectangle or approximately rectangle). The minor axis Y may be defined as the direction perpendicular to the major axis X in the shape of the projection of the sound generating unit 11 onto the sagittal plane (for example, if the projection shape is rectangular or approximately rectangular, the minor axis is the width direction of the rectangle or approximately rectangle). The thickness direction Z may also be defined as the direction perpendicular to the two-dimensional projection plane, for example, coinciding with the direction of the coronal axis, both of which point in the left-right direction of the body.

[0057] In some embodiments, when a user wears the open-type earphone 10, the sound generating unit 11 may be fixed in a position near the user's external auditory canal 101 so as not to block the ear canal. In some embodiments, when worn, the projection of the open-type earphone 10 onto the sagittal plane does not have to cover the user's ear canal. For example, the projection of the sound generating unit 11 onto the sagittal plane may be on both the left and right sides of the head and located in front of the tragus on the sagittal axis of the human body (for example, the position shown by the solid line frame A in Figure 2). In this case, the sound generating unit 11 is located in front of the user's tragus, the long axis of the sound generating unit 11 may be vertical or nearly vertical, the projection onto the sagittal plane in the short axis direction Y coincides with the direction of the sagittal axis, the projection onto the sagittal plane in the long axis direction X coincides with the vertical axis direction, and the thickness direction Z is perpendicular to the sagittal plane. Alternatively, for example, the projection of the sound generating unit 11 onto the sagittal plane may be located on the antihelix 105 (for example, the position shown by the dashed line frame C in Figure 2). In this case, the sound generating unit 11 is located at least partially on the antihelix 105, the long axis of the sound generating unit 11 is horizontal or nearly horizontal, the projection of the sound generating unit 11 in the long axis direction X onto the sagittal plane coincides with the direction of the sagittal axis, the projection of the short axis direction Y onto the sagittal plane coincides with the vertical axis, and the thickness direction Z is perpendicular to the sagittal plane. This avoids the sound generating unit 11 covering the ear canal, leaving both of the user's ears free, increasing the contact area between the sound generating unit 11 and the ear portion 100, and improving the wearing comfort of the open-type earphone 10.

[0058] In some embodiments, when worn, the sagittal projection of the open-type earphone 10 may cover, or at least partially cover, the user's ear canal. For example, the sagittal projection of the sound generating unit 11 may be located within the concha 102 (e.g., at the position shown in dashed frame B in Figure 2) and in contact with the helix crus 1071 and / or helix 107. In this case, the sound generating unit 11 is located at least partially within the concha 102, the sound generating unit 11 is inclined, the sagittal projection of the sound generating unit 11 in the short axis direction Y may have a constant angle with respect to the sagittal axis direction, i.e., the short axis direction Y is also inclined accordingly, the sagittal projection of the sound generating unit 11 in the long axis direction X may have a constant angle with respect to the sagittal axis direction, i.e., the long axis direction X is also inclined, and the thickness direction Z is perpendicular to the sagittal plane. In this case, since the concha 102 has a certain volume and depth, there is a certain gap between the inner surface IS of the open-type earphone 10 and the concha 10, and the ear canal communicates with the outside through the gap between the inner surface IS and the concha 10, freeing both of the user's ears. In addition, the sound generating part 11 and the concha 10 can cooperate to form an auxiliary cavity (for example, a cavity structure described later) that communicates with the ear canal. In some embodiments, the sound vent 112 may be located at least partially within the auxiliary cavity, and the sound emitted from the sound vent 112 is restricted by the auxiliary cavity, that is, the auxiliary cavity can focus the sound and propagate more of the sound into the ear canal, thereby improving the volume and quality of the sound heard by the user in the near field and improving the acoustic effect of the open-type earphone 10.

[0059] The above description of the open-type earphone 10 is for illustrative purposes only and is not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications based on the description. For example, the open-type earphone 10 may include a battery assembly, a Bluetooth® assembly, or a combination thereof. The battery assembly is used to supply power to the open-type earphone 10. The Bluetooth® assembly allows the open-type earphone 10 to be wirelessly connected to other devices (e.g., mobile phones, computers, etc.). These changes and modifications remain within the scope of protection of this application.

[0060] Figure 3 is a schematic diagram of two point sources and a listening position according to some embodiments of the present application. In some embodiments, as shown in Figure 3, sound can be transmitted to the outside of the open-type earphone 10 through the sound emission hole 112, which can be considered a monopole sound source (or point source) A1 to generate a first sound, and sound can be transmitted to the outside of the open-type earphone 10 through the pressure reduction hole 113, which can be considered a monopole sound source (or point source) A2 to generate a second sound, the second sound and the first sound may have opposite or nearly opposite phases and can cancel each other out in the far field, that is, form an "acoustic dipole" to reduce sound leakage. In some embodiments, the connecting wires of the two monopole sound sources may be directed towards the ear canal (referred to as the "listening position") so that the user can hear a sufficiently loud sound when wearing the earphone. The magnitude of the sound pressure at the listening position (referred to as Pear) can represent the intensity of the sound heard by the user (i.e., near-field listening sound pressure). Furthermore, the magnitude of the sound pressure (denoted as Pfar) on a sphere centered on the user's listening position (or on a sphere with radius r, with the center of the dipole sound sources (A1 and A2 shown in Figure 3) as the center) can be statistically determined, and the strength of sound leakage from the open-type earphones 10 to the far field (i.e., the sound leakage sound pressure in the far field) can be represented. Pfar can be obtained using various statistical methods; for example, the average sound pressure at each point on the sphere can be calculated, and further, for example, the sound pressure distribution at each point on the sphere can be calculated and surface integral can be performed.

[0061] The sound leakage measurement method described in this application is merely an illustrative explanation of the principle and effect, and is not limiting. The sound leakage measurement and calculation methods may be reasonably adjusted according to the actual situation. For example, the center of a dipole sound source is taken as the center of a circle, and the sound pressure amplitudes of two or more points are equally selected and averaged based on a constant spatial angle in the far field. In some embodiments, the listening measurement method may involve selecting one position point near the point source as the listening position, and taking the sound pressure amplitude measured at the listening position as the listening value. In some embodiments, the listening position may be on the line connecting the two point sources, or it may not be on the line connecting the two point sources. The listening measurement and calculation methods may be reasonably adjusted according to the actual situation. For example, the sound pressure amplitudes of other points or one or more points at the near-field position are averaged. Alternatively, for example, a certain point source is taken as the center of a circle, and the sound pressure amplitudes of two or more points are equally selected and averaged based on a constant spatial angle in the near field. In some embodiments, the distance between the near-field listening position and the point source is much smaller than the distance between the point source and the far-field sound leakage measurement sphere.

[0062] Clearly, the sound pressure Pear transmitted from the open-type earphone 10 to the user's ear should be sufficiently large to improve the listening effect. The far-field sound pressure Pfar should be sufficiently small to improve the sound leakage reduction effect. Therefore, the sound leakage index α can be used as an indicator to evaluate the sound leakage reduction capability of the open-type earphone 10.

[0063]

number

[0064] As can be seen from equation (1), the smaller the sound leakage index, the better the sound leakage reduction capability of open-type earphones, and when the near-field listening volume at the listening position is the same, far-field sound leakage will be smaller.

[0065] Figure 4 is a comparative diagram of the sound leakage index at different frequencies for single-point and dual-point sound sources according to several embodiments of the present invention. The dual-point sound source (also called a dipole sound source) in Figure 4 may be a typical dual-point sound source, that is, the spacing is constant, the amplitudes of the two point sound sources are the same, and the phases of the two point sound sources are opposite. Note that the selection of a typical dual-point sound source is for the purpose of explaining the principle and effect only, and the parameters of each point sound source can be adjusted according to actual needs to create a certain difference from a typical dual-point sound source. As shown in Figure 4, when the spacing is constant, the sound leakage generated by the dual-point sound source increases with increasing frequency, and the sound leakage reduction ability weakens with increasing frequency. When the frequency is greater than a certain frequency value (for example, about 8000 Hz as shown in Figure 4), the generated sound leakage is greater than that of a single-point sound source, and this frequency (for example, 8000 Hz) is the upper frequency limit at which the dual-point sound source can reduce sound leakage.

[0066] In some embodiments, a baffle may be installed between the sound outlet 112 and the pressure reducing hole 113 to improve the acoustic output effect of the open-type earphone 10, that is, to increase the sound intensity at the near-field listening position and to reduce the volume of far-field sound leakage.

[0067] Figure 5 is an exemplary distribution schematic diagram of a case in which a baffle is installed between two sound sources of a dipole sound source according to some embodiments of the present application. As shown in Figure 5, when a baffle is installed between point source A1 and point source A2, in the near field, the sound waves of point source A2 can interfere with the sound waves of point source A1 at the listening position only by bypassing the baffle, which corresponds to an increase in the acoustic distance from point source A2 to the listening position. Therefore, assuming that point source A1 and point source A2 have the same amplitude, the amplitude difference of the sound waves of point source A1 and point source A2 at the listening position increases compared to when no baffle is installed, and as a result the degree to which the sounds from the two paths cancel each other out at the listening position decreases, and the volume at the listening position increases. In a far-field environment, sound waves generated by point sources A1 and A2 can interfere with each other within a wide spatial range without bypassing the baffle (similar to the case without a baffle). Therefore, far-field sound leakage does not significantly increase compared to the case without a baffle. Consequently, by installing a baffle structure around one of the point sources A1 and A2, the volume at the near-field listening position can be significantly increased without a significant increase in far-field sound leakage volume.

[0068] Figure 6 shows the sound leakage index for several embodiments of the present invention, with and without a baffle installed between the two sound sources of a dipole sound source. After adding a baffle to the dual-point sound source, in the near field, it is equivalent to increasing the distance between the two point sound sources. The volume at the near-field listening position is equivalent to that generated by a dual-point sound source at a greater distance, and the listening volume in the near field is clearly increased compared to the case without a baffle. In the far field, the sound field of the two point sound sources is less affected by the baffle, and the resulting sound leakage is equivalent to that generated by a dual-point sound source at a smaller distance. Therefore, as shown in Figure 6, after adding a baffle, the sound leakage index is significantly smaller compared to the case without a baffle. That is, at the same listening volume, the sound leakage in the far field is smaller than in the case without a baffle, and the sound leakage reduction capability is clearly stronger.

[0069] Figure 7 is an illustrative schematic diagram of how an open-type earphone can be worn according to some embodiments of the present invention. Figure 8 is a schematic diagram of the ear-facing side of the open-type earphone shown in Figure 7. Figure 9 is a schematic diagram of the housing of the open-type earphone shown in Figure 7.

[0070] As shown in Figure 7, the ear hook 12 has an arc-shaped structure that fits the boundary between the user's head and ear portion 100. The sound generating unit 11 (or the housing 111 of the sound generating unit 11) may have a connection end CE connected to the ear hook 12 and a free end FE not connected to the ear hook 12. When the open-type earphone 10 is worn, the first portion 121 of the ear hook 12 (e.g., the hook-shaped portion of the ear hook 12) is placed between the user's auricle (e.g., helix 107) and head, and the second portion 122 of the ear hook 12 (e.g., the connection portion of the ear hook) extends to the side of the auricle away from the head and is connected to the connection end CE of the sound generating unit 11, fixing the sound generating unit 11 in a position near the ear canal so as not to block the ear canal.

[0071] As shown in Figures 7 and 8, the sound generating unit 11 may, when worn, have an inner surface IS (also called the inner surface of the housing 111) that faces the ear along the thickness direction Z, an outer surface OS (also called the outer surface of the housing 111) that moves away from the ear, and a connecting surface that connects the inner surface IS and the outer surface OS. When worn, the sound generating unit 11 may be installed in a circular, elliptical, rounded square, rounded rectangle, or the like, when viewed from the direction in which the coronal axis is located (i.e., the thickness direction Z). When the sound generating unit 11 is installed in a circular, elliptical, or the like, the connecting surface may be an arc-shaped side of the sound generating unit 11, and when the sound generating unit 11 is installed in a rounded square, rounded rectangle, or the like, the connecting surface may include the lower surface LS (also called the lower surface of the housing 111), the upper surface US (also called the upper surface of the housing 111), and the rear surface RS (also called the rear surface of the housing 111), which will be described later. The upper side US and lower side LS may be the side where the sound generating unit 11 moves away from the external auditory canal 101 and the side where it approaches the external auditory canal 101, respectively, along the short axis Y when worn, and the rear side RS may be the side where the sound generating unit 11 faces backward towards the head along the length direction X when worn. For convenience of explanation, this specification illustrates the case in which the sound generating unit 11 is set as a rounded rectangle. The length of the sound generating unit 11 in the long axis direction X may be greater than the width of the sound generating unit 11 in the short axis direction Y. In some embodiments, the rear side RS of the earphone may be an arcuate surface in order to improve the aesthetics and wearing comfort of the earphone.

[0072] A transducer capable of generating sound by converting electrical signals into corresponding mechanical vibrations may be installed within the sound generating unit 11. The transducer (e.g., a diaphragm) can partition the housing 111 to form the front cavity and rear cavity of the earphone. The sound generated in the front cavity and rear cavity has opposite phase. A sound discharge hole 112 communicating with the front cavity is formed on the inner surface IS to guide the sound generated in the front cavity out of the housing 111 and transmit it to the ear canal so that the user can hear the sound. One or more depressurization holes 113 communicating with the rear cavity may be formed on other sides of the housing 111 (e.g., outer surface OS, upper surface US, or lower surface LS, etc.), so that the sound generated in the rear cavity, after being guided out of the housing 111, interferes with and cancels out the sound leaking through the sound discharge hole 112 in the far field. In some embodiments, the decompression port 113 is located further from the ear canal than the sound outlet 112, reducing the phase cancellation at the listening position (e.g., the ear canal) between the sound output through the decompression port 113 and the sound output through the sound outlet 112, thereby increasing the volume of the sound at the listening position.

[0073] In some embodiments, in addition to the inner surface IS, at least two depressurization holes 113 may be formed on other surfaces of the housing 111 (e.g., the outer surface OS, upper surface US, or lower surface LS). By providing at least two depressurization holes 113, standing waves in the rear cavity can be destroyed, and by raising the resonant frequency of the sound led out from the depressurization holes 113 to the outside of the housing 111 as high as possible, the frequency response of the rear cavity will have a wide flat region (e.g., the region before the resonant peak) and will achieve a higher sound leakage reduction effect in the mid-to-high frequency range (e.g., 2kHz to 6kHz). As just one example, the depressurization holes 113 may include a first depressurization hole 1131 and a second depressurization hole 1132. The second depressurization hole 1132 may be closer to the sound emission hole 112 than the first depressurization hole 1131. In some embodiments, the first depressurization hole 1131 and the second depressurization hole 1132 may be located on the same side of the housing 111. For example, the first depressurization hole 1131 and the second depressurization hole 113 may be located simultaneously on the outer side OS, the upper side US, or the lower side LS. In some embodiments, the first depressurization hole 1131 and the second depressurization hole 1132 may be located on two different sides of the housing 111. For example, the first depressurization hole 1131 may be located on the outer side OS and the second depressurization hole 1132 may be located on the upper side US, or the first depressurization hole 1131 may be located on the outer side OS and the second depressurization hole 1132 may be located on the lower side LS. In some embodiments, to maximize the disruption of standing waves in the rear cavity, the two depressurization holes 113 may be located on opposite sides of the housing 111, for example, the first depressurization hole 1131 may be located on the upper side US and the second depressurization hole 1132 may be located on the lower side LS. For convenience of explanation, this specification illustrates the case in which the first depressurization hole 1131 is located on the upper side US and the second depressurization hole 1132 is located on the lower side LS.

[0074] In some embodiments, in order to avoid the sound output from the first depressurization hole 1131 and the second depressurization hole 1132 affecting the volume of the sound output from the sound outlet 112 at the listening position, the first depressurization hole 1131 and the second depressurization hole 1132 should be as far away from the sound outlet 112 as possible. For example, the center of the sound outlet 112 may be located on or near the perpendicular bisector plane of the connecting line between the center of the first depressurization hole 1131 and the center of the second depressurization hole 1132. In some embodiments, the center of the sound outlet 112 may be 0 mm to 2 mm away from the perpendicular bisector plane of the connecting line between the center of the first depressurization hole 1131 and the center of the second depressurization hole 1132. In some embodiments, in order to further avoid the reduction in listening volume caused by the sound emitted from the second decompression hole 1132 canceling out in opposite phase with the sound emitted from the sound emission hole 112 in the ear canal (i.e., listening position), the area of ​​the second decompression hole 1132 may be reduced to reduce the intensity of the sound that is led out from the second decompression hole 1132 and transmitted to the ear canal. In this case, the area of ​​the second decompression hole 1132 may be smaller than the area of ​​the first decompression hole 1131 (shown in Figure 16).

[0075] In some embodiments, as shown in Figure 7, when the open-type earphone 10 is worn, the longitudinal axis X of the sound generating unit 11 may be positioned horizontally or substantially horizontally (similar to position C shown in Figure 2). In this case, the sound generating unit 11 is at least partially located on the antihelix 105, and the free end FE of the sound generating unit 11 may face the back of the head. The sound generating unit 11 is in a horizontal or substantially horizontal position, the projection of the longitudinal axis X of the sound generating unit 11 onto the sagittal plane coincides with the direction of the sagittal axis, the projection of the minor axis Y onto the sagittal plane coincides with the vertical axis, and the thickness direction Z may be perpendicular to the sagittal plane.

[0076] In some embodiments, in order to improve the fit between the open-type earphone 10 and the ear portion 100 and to improve the stability of wearing the open-type earphone 10, the inner surface IS of the housing 111 may be pressed against the surface of the ear portion 100 (e.g., antihelix 105) to increase resistance to the open-type earphone 10 falling out of the ear portion 100.

[0077] In some embodiments, as shown in Figures 7 and 8, when the open-type earphone 10 is pressed against the ear portion 100, the projection of the sound-emitting hole 112 onto the sagittal plane may overlap with the projection onto the sagittal plane of a structure (e.g., the concha 103) that is inwardly recessed in the ear portion, so that the sound-emitting hole 112 on the inner surface IS is not obstructed by the tissue of the ear portion. In some embodiments, since the concha 103 communicates with the concha cavity 102 and the ear canal is located within the concha cavity 102, when at least a portion of the projection of the sound-emitting hole 112 onto the sagittal plane is located within the concha 103, the sound output from the sound-emitting hole 112 can reach the ear canal without obstruction, and the volume received by the ear canal is increased. In some embodiments, the longitudinal dimension of the sound-generating unit 11 should not be too long, as if it is, the projection of the free end FE onto the sagittal plane will exceed the projection of the ear portion onto the sagittal plane, affecting the fit effect between the sound-generating unit 11 and the ear portion. Therefore, the longitudinal dimension of the sound generating unit 11 can be designed such that the projection of the free end FE onto the sagittal plane does not exceed the projection of the helix 107 onto the sagittal plane.

[0078] The sound vents 112 and pressure relief holes 113 (for example, the first pressure relief hole 1131 and the second pressure relief hole 1132) are installed in the housing 111, and since each side wall of the housing 111 has a constant thickness, the sound vents 112 and pressure relief holes 113 are holes with a constant depth. In this case, the sound vents 112 and pressure relief holes 113 may both have an inner opening and an outer opening. For the sake of explanation, in this application, the center O of the sound vents 112 described above and below may be the centroid of the outer opening of the sound vents 112, and the center of the pressure relief holes 113 described above and below may be the centroid of the outer opening of the pressure relief hole 113 (for example, the center O1 of the first pressure relief hole 1131 may be the centroid of the outer opening of the first pressure relief hole 1131, and the center O2 of the second pressure relief hole 1132 may be the centroid of the outer opening of the second pressure relief hole 1132). For the sake of explanation, in this specification, the areas of the sound vents 112 and depressurization holes 113 (for example, the first depressurization hole 1131 and / or the second depressurization hole 1132) may be the areas of the outer openings of the sound vents 112 and depressurization holes 113 (for example, the outer opening area on the inner surface IS of the sound vent 112, the outer opening area on the upper surface US of the first depressurization hole 1131, and the outer opening area on the lower surface LS of the second depressurization hole 1132). In some other embodiments, the areas of the sound vents 112 and depressurization holes 113 may be other cross-sectional areas of the sound vents 112 and depressurization holes 113, for example, the area of ​​the inner openings of the sound vents 112 and / or depressurization holes 113, or the average value of the inner opening area and the outer opening area of ​​the sound vents 112 and / or depressurization holes 113.

[0079] In some embodiments, the sound vents 112 communicating with the front cavity can be considered as point source A1 as shown in Figure 5, the pressure relief holes 113 communicating with the rear cavity (e.g., a first pressure relief hole 1131 and / or a second pressure relief hole 1132) can be considered as point source A2 as shown in Figure 5, and the ear canal can be considered as the listening position as shown in Figure 5. At least a portion of the housing and / or at least a portion of the auricle of the sound generating unit 11 can be considered as a baffle as shown in Figure 5, increasing the difference in acoustic distance from the sound vents 112 to the ear canal, thereby increasing the intensity of sound in the ear canal and maintaining the effect of reducing sound leakage in the far field. When the open-type earphone 10 uses the structure shown in Figure 7, that is, when at least a part of the housing 111 is located on the antihelix 105, in terms of listening effect, the sound waves from the sound vent 112 can directly reach the ear canal. In this case, the sound vent 112 may be positioned close to the lower surface LS on the inner surface IS, and at least one decompression hole may be positioned away from the sound vent 112. For example, the first decompression hole 1131 may be positioned away from the sound vent 112 on the outer surface OS or upper surface US. The sound waves from the first decompression hole 1131 must bypass the outside of the sound generating unit 11 so as to interfere with the sound waves from the sound vent 112 in the ear canal. Furthermore, an upwardly convex and downwardly concave structure in the auricle (for example, the antihelix, tragus, etc. in its propagation path) also increases the acoustic distance over which the sound from the first decompression hole 1131 is conducted to the ear canal. Therefore, the sound generating unit 11 itself and / or at least a portion of the auricle act as a baffle between the sound vent 112 and the first depressurization vent 1131. The baffle increases the acoustic distance of sound from the first depressurization vent 1131 to the ear canal, reduces the intensity of the sound waves from the first depressurization vent 1131 in the ear canal, and thereby reduces the degree of cancellation of the sound emitted by the sound vent 112 and the first depressurization vent 1131 in the ear canal, thereby increasing the volume in the ear canal. In terms of sound leakage, the sound waves generated by the sound vent 112 and the first depressurization vent 1131 and / or the second depressurization vent 1132 can interfere with each other within a wide spatial range without bypassing the sound generating unit 11 itself (similar to the case without a baffle), so sound leakage does not significantly increase.Therefore, by setting the appropriate positions of the sound emission hole 112, the first pressure reduction hole 1131, and the second pressure reduction hole 1132, it is possible to significantly increase the volume in the ear canal without significantly increasing the volume of sound leakage.

[0080] In some embodiments, when the projection of the free end FE onto the sagittal plane does not exceed the projection of the helix 107 onto the sagittal plane, the first decompression holes 1131 and the second decompression holes 1132 may be distributed substantially symmetrically with respect to the long axis central plane of the sound generating unit 11 (for example, the back surface NN' perpendicular to the plane of the paper as shown in Figure 8) to facilitate production and manufacturing. In some embodiments, the difference between the distance a2 from the center O2 of the second decompression hole 1132 on the lower side surface LS to the rear side surface RS and the distance a1 from the center O1 of the first decompression hole 1131 on the upper side surface US to the rear side surface RS is less than 10%. In some embodiments, the difference between the distance a2 from the center O2 of the second decompression hole 1132 on the lower side surface LS to the rear side surface RS and the distance a1 from the center O1 of the first decompression hole 1131 on the upper side surface US to the rear side surface RS is less than 5%. In some embodiments, the difference between the distance a2 from the center O2 of the second pressure relief hole 1132 on the lower side LS to the rear side RS and the distance a1 from the center O1 of the first pressure relief hole 1131 on the upper side US to the rear side RS is less than 2%. In some embodiments, the rear side RS of the earphone may be an arcuate surface in order to improve the aesthetics and wearing comfort of the earphone. When the rear side RS is an arcuate surface, the distance from a certain position (for example, the center O1 of the first pressure relief hole 1131) to the rear side RS may be the distance from that position to a tangent plane parallel to the minor axis of the rear side RS.

[0081] In some embodiments, the sound vent 112 is positioned close to the ear canal, and the second decompression hole 1132 on the lower side LS should be positioned as far away from the sound vent 112 as possible. This reduces the effect of sound emitted from the second decompression hole 1132 canceling out sound emitted from the sound vent 112 at the listening position (i.e., the ear canal), and further increases the volume at the listening position. Therefore, when the sound vent 112 is positioned close to the lower side LS and the connecting end CE, the distance between the sound vent 112 and the second decompression hole 1132 can be made as large as possible by positioning the second decompression hole 1132 close to the rear side RS. In some embodiments, when the projection of the free end FE into the sagittal plane does not exceed the projection of the helix 107 into the sagittal plane, the range of the distance a2 from the center O2 of the second decompression hole 1132 to the rear side RS may be 8.60 mm to 20.27 mm. In some embodiments, the distance a2 from the center O2 of the second pressure relief hole 1132 to the rear side RS may be in the range of 8.60 mm to 12.92 mm. In some embodiments, the distance a2 from the center O2 of the second pressure relief hole 1132 to the rear side RS may be in the range of 9.60 mm to 11.92 mm. In some embodiments, when the open-type earphone 10 is worn, the free end FE may come into contact with the ear (e.g., helix 107), and a portion of the upper side US and / or lower side LS may be shielded by the ear. In this case, to avoid the second pressure relief hole 1132 on the lower side LS (or the first pressure relief hole 1131 on the upper side US) being shielded by the ear 100 and affecting the acoustic performance of the open-type earphone 10, the distance a2 from the center O2 of the second pressure relief hole 1132 to the rear side RS may be in the range of 10.10 mm to 11.42 mm. More preferably, the distance a2 from the center O2 of the second decompression hole 1132 to the rear side RS may be in the range of 10.30 mm to 11.12 mm. More preferably, the distance a2 from the center O2 of the second decompression hole 1132 to the rear side RS may be in the range of 10.60 mm to 11.82 mm.

[0082] In some embodiments, if the difference between the distance a2 from the center O2 of the second decompression hole 1132 to the rear side RS and the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS is less than 10%, the range of the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be 8.60 mm to 15.68 mm. In some embodiments, the range of the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be 8.60 mm to 12.92 mm. In some embodiments, in order to make the projection of the first decompression hole 1131 onto the sagittal plane approximately coincide with the projection of the inwardly recessed structure of the ear portion onto the sagittal plane, the range of the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be 9.60 mm to 11.92 mm. Preferably, the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be in the range of 10.10 mm to 11.42 mm. More preferably, the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be in the range of 10.30 mm to 11.12 mm. More preferably, the distance a1 from the center O1 of the first decompression hole 1131 to the rear side RS may be in the range of 10.60 mm to 11.82 mm.

[0083] In some embodiments, the first decompression hole 1131 may be further from the sound emission hole 112 than the second decompression hole 1132, and because the gap between the ear portion 100 and the inner surface IS is small, sound generated in the first decompression hole 1131 is less likely to be transmitted to the ear canal compared to the second decompression hole 1132. Therefore, in some embodiments, the distance from the center O1 of the first decompression hole 1131 to the rear surface RS may be smaller than the distance from the center O2 of the second decompression hole 1132 to the rear surface RS. For example, the range of the distance from the center O1 of the first decompression hole 1131 to the rear surface RS is 10.44 mm to 15.68 mm, and the range of the distance from the center O2 of the second decompression hole 1132 to the rear surface RS is 13.51 mm to 20.27 mm.

[0084] In some embodiments, as shown in Figure 9, the acoustic efficiency of the open-type earphone 10 (i.e., listening volume at the listening position) can be improved by increasing the dimension of the open-type earphone 10 in the thickness direction Z in order to increase the acoustic distance from the first depressurization hole 1131 and / or the second depressurization hole 1132 to the ear canal. Furthermore, by positioning the first depressurization hole 1131 and / or the second depressurization hole 1132 away from the inner surface IS, the acoustic distance from the first depressurization hole 1131 and / or the second depressurization hole 1132 to the ear canal can be further increased, thereby improving the acoustic efficiency of the open-type earphone 10. Also, the overall dimensions of the acoustic generating part 11 should not be too large (for example, the dimensions of the acoustic generating part 11 in the Z direction should not be too large), otherwise the overall mass of the open-type earphone 10 will increase, affecting the user's wearing comfort. In some embodiments, the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS ranges from 4.24 mm to 7.96 mm. In some embodiments, the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS ranges from 4.43 mm to 7.96 mm. In some embodiments, the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS ranges from 5.43 mm to 6.96 mm. In some embodiments, the first decompression holes 1131 and / or the second decompression holes 1132 may be positioned away from the inner surface IS to achieve the objective of allowing sound output from the first decompression holes 1131 and / or the second decompression holes 1132 to be radiated more outward rather than being transmitted to the ear canal or reflected and refracted by some structure of the ear part 100 (e.g., the auricle) and transmitted to the ear canal, by having the projection of the first decompression hole 1131 onto the horizontal plane slightly overlap with or not overlap with the projection of the ear part 100 onto the horizontal plane. By positioning them in this way, the acoustic distance from the first decompression holes 1131 and / or the second decompression holes 1132 to the ear canal can be further increased, thereby improving the sound generation efficiency of the open-type earphone 10. In some embodiments, the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS ranges from 5.63 mm to 7.96 mm.In some embodiments, the distance d1 from the center O1 of the first depressurization hole 1131 to the inner surface IS ranges from 6.25 mm to 7.56 mm.

[0085] In some embodiments, the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS may be the same as the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS. In some embodiments, the range of the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS is 4.43 mm to 7.96 mm. In some embodiments, the range of the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS is 5.43 mm to 6.96 mm. In some embodiments, the range of the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS is 5.63 mm to 7.96 mm. In some embodiments, the range of the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS is 6.25 mm to 7.56 mm.

[0086] In some embodiments, the sound vent 112 needs to be brought close to the lower surface LS in order to bring it closer to the ear canal and increase the listening position. In this case, the second decompression vent 1132 is closer to the inner surface IS than the first decompression vent 1131. To reduce the effect of the sound emitted from the second decompression vent 1132 canceling out the sound emitted from the sound vent 112 at the listening position (i.e., the ear canal), and to further increase the volume at the listening position, in the Z direction, the second decompression vent 1132 may be further away from the inner surface IS than the first decompression vent 1131, that is, the distance d2 from the center O2 of the second decompression vent 1132 to the inner surface IS may be different from the distance d1 from the center O1 of the first decompression vent 1131 to the inner surface IS. For example, the distance d1 from the center O1 of the first decompression hole 1131 to the inner surface IS ranges from 5.63 mm to 6.5 mm, and the distance d2 from the center O2 of the second decompression hole 1132 to the inner surface IS ranges from 6.5 mm to 7.56 mm.

[0087] The above description of the open-type earphone 10 is for illustrative purposes only and is not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications based on the description of this application. For example, if only one depressurization hole is installed in the sound generating unit 11, the depressurization hole may be either the first depressurization hole 1131 or the second depressurization hole 1132. For example, the depressurization hole may be the first depressurization hole 1131, that is, it may be installed on the upper side surface US. The distance from the center of the depressurization hole to the inner side surface IS may be in the range of 4.24 mm to 7.96 mm, and the distance from the center of the depressurization hole to the rear side surface RS may be in the range of 8.60 mm to 15.68 mm. These changes and modifications remain within the scope of protection of this application.

[0088] In some embodiments, a cavity structure can be constructed around one of the dipole sources to increase the listening volume, particularly the mid-to-low frequency listening volume, while still retaining the effect of far-field sound leakage cancellation. Figure 10 is an exemplary distribution schematic diagram of a case in which a cavity structure is installed around one of the dipole sources according to some embodiments of the present application.

[0089] As shown in Figure 10, when a cavity structure 41 is placed between dipole sound sources, one of the dipole sound sources and the listening position are inside the cavity structure 41, and the other dipole sound source is outside the cavity structure 41. The sound derived from the dipole sound source inside the cavity structure 41 is restricted by the cavity structure 41, that is, the cavity structure 41 converges the sound and allows more of the sound to propagate into the listening position, thereby improving the volume and quality of the sound at the listening position. In this application, the “cavity structure” may be understood as a semi-sealed structure surrounded by the side wall of the sound generating unit 11 and the concha cavity structure, and the semi-sealed structure does not completely seal and isolate the internal and external environments, but rather has a leakage structure 42 (e.g., openings, gaps, conduits, etc.) that allows acoustic communication with the external environment. Exemplary leakage structures may include, but are not limited to, openings, gaps, conduits, etc., or any combination thereof.

[0090] In some embodiments, the cavity structure 41 may include a listening position and at least one sound source. Here, "includes" may mean that at least one of the listening position and the sound source is located inside the cavity, or at least one of the listening position and the sound source is located at the edge inside the cavity. In some embodiments, the listening position may be the entrance to the ear canal, or it may be the acoustic reference point of the ear.

[0091] Figure 11A is a schematic diagram of the listening principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources, according to some embodiments of the present application. Figure 11B is a schematic diagram of the sound leakage principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources, according to some embodiments of the present application.

[0092] For near-field listening, in a dipole setup as shown in Figure 11A, where a cavity structure is built around one of the sound sources, the majority of the sound emitted by sound source A reaches the listening position either directly or reflected, because A is enclosed within the cavity structure. In contrast, without a cavity structure, the majority of the sound emitted from the sound source does not reach the listening position. Therefore, by installing a cavity structure, the volume of sound reaching the listening position can be significantly increased. Furthermore, only a small portion of the out-of-phase sound emitted from out-of-phase sound source B outside the cavity structure enters the cavity structure through its leakage structure. This corresponds to the generation of a secondary sound source B' in the leakage structure, and its intensity is significantly lower than that of sound source B and significantly lower than that of sound source A. The sound generated by secondary sound source B' has a weak out-of-phase cancellation effect on sound source A within the cavity, thereby significantly increasing the listening volume at the listening position.

[0093] Regarding sound leakage, as shown in Figure 11B, the radiation of sound source A to the outside through the leakage structure of the cavity is equivalent to the generation of a secondary sound source A' in the leakage structure. Almost all of the sound radiated from sound source A is output from the leakage structure, and since the structural scale of the cavity is much smaller (at least an order of magnitude smaller) than the spatial scale used to evaluate sound leakage, the intensity of the secondary sound source A' is considered to be equivalent to the intensity of sound source A. The sound cancellation effect generated by the secondary sound source A' and sound source B with respect to the external space is equivalent to the sound cancellation effect generated by sound source A and sound source B. In other words, this cavity structure still maintains a considerable sound leakage reduction effect.

[0094] It should be noted that the leakage structure with one opening described above is merely illustrative, and the leakage structure of the cavity structure may include one or more openings, achieving an excellent listening index. The listening index may also be the reciprocal of the sound leakage index α, which is 1 / α. Using a structure with two openings as an example, the cases of equal openings and equal opening ratio are analyzed below. Compared to a structure with only one hole, "equal openings" here means installing two openings of the same dimensions as the structure with only one hole, and "equal opening ratio" means that the sum of the opening areas of the two installed holes is the same as the structure with only one hole. Equal openings correspond to doubling the relative size of the openings in a structure with only one hole (i.e., the ratio of the opening area S of the leakage structure in the cavity structure to the area S0 directly affected by the sound source contained in the cavity structure), and as mentioned earlier, the overall listening index decreases. In the case of equal perforation ratio, even if the S / S0 is the same as a structure with only one hole formed, the different distances from the two openings to the external sound source result in different listening indices.

[0095] Figure 12A is a schematic diagram of a cavity structure having two horizontal openings according to some embodiments of the present application. Figure 12B is a schematic diagram of a cavity structure having two vertical openings according to some embodiments of the present application. As shown in Figure 12A, when the connecting lines of the two openings are parallel to the connecting lines of the two sound sources (i.e., they are two horizontal openings), the distances from the two openings to the external sound sources are the maximum and minimum, respectively. As shown in Figure 12B, when the connecting lines of the two openings are perpendicular to the connecting lines of the two sound sources (i.e., they are two vertical openings), the distances from the two openings to the external sound sources are equal and take an intermediate value.

[0096] Figure 13 is a comparison of listening index curves for a cavity structure with two openings and a cavity structure with one opening, according to several embodiments of the present application. As shown in Figure 13, the listening index of the cavity structure with equal openings is lower overall compared to the cavity structure with one opening. This is because the distance from the two openings to the external sound source is different for the cavity structure with equal opening ratios. As can be seen from Figures 12A, 12B, and 13, the listening index of the leakage structure with equal opening ratios is higher than that of the leakage structure with equal openings, whether for horizontal or vertical openings. This is because the relative opening size S / S0 of the leakage structure with equal opening ratios is reduced to half that of the leakage structure with equal opening ratios, resulting in a higher listening index. Also, as can be seen from Figures 12A, 12B, and 13, the listening index for horizontal openings is higher for both the leakage structure with equal opening ratios and the leakage structure with equal opening ratios. This is because, in a horizontal opening leakage structure, the distance from one of the openings to the external sound source is smaller than the distance between the two sound sources, and the distance between the thus formed secondary sound source and the external sound source is closer to the original two sound sources, resulting in a higher listening index and further improving the sound leakage reduction effect. Therefore, in order to improve the sound leakage reduction effect, the distance from at least one opening to the external sound source may be made smaller than the distance between the two sound sources.

[0097] Furthermore, as shown in Figure 13, a cavity structure using two openings can better improve the resonant frequency of airborne sound within the cavity structure compared to a cavity structure with one opening. As a result, the entire device has a better listening index in the high-frequency range (e.g., sounds with frequencies close to 10,000 Hz) compared to a cavity structure with only one opening. The need for sound leakage reduction is greater in the high-frequency range because the human ear is more sensitive to this range. Therefore, to improve the sound leakage reduction effect in the high-frequency range, a cavity structure with more than one opening may be selected.

[0098] Figure 14 is a schematic diagram illustrating the wearing of an exemplary open-type earphone according to some other embodiments of the present invention. Figure 15 is a schematic configuration diagram of the ear-facing side of the open-type earphone shown in Figure 14.

[0099] The open-type earphone 10 shown in Figure 14 has a structure similar to the open-type earphone 10 shown in Figure 7, for example, the ear hook 12 has an arc-shaped structure that fits the boundary between the user's head and ear portion 100. The sound generating unit 11 (or the housing 111 of the sound generating unit 11) may have a connection end CE connected to the ear hook 12 and a free end FE not connected to the ear hook 12. When the open-type earphone 10 is worn, the first portion 121 of the ear hook 12 (for example, the hook-shaped portion of the ear hook 12) is placed between the user's auricle (for example, the helix 107) and head, and the second portion 122 of the ear hook 12 (for example, the connection portion of the ear hook) extends to the side of the auricle away from the head and is connected to the connection end CE of the sound generating unit 11, fixing the sound generating unit 11 in a position near the ear canal so as not to block the ear canal. The open-type earphone 10 shown in Figure 14 is similar in structure to the open-type earphone 10 shown in Figure 7, the main difference being that the sound generating unit 11 is installed at an angle, and the housing 111 of the sound generating unit 11 is inserted at least partially into the concha 102, or for example, the free end FE of the sound generating unit 11 may be inserted into the concha 102. An ear hook 12 and sound generating unit 11 having such a structure offers a high degree of fit with the user's ear 100 and can improve the wearing stability of the open-type earphone 10 by increasing resistance to the open-type earphone 10 falling off the ear 100.

[0100] In some embodiments, when worn, the connection end CE of the sound generating unit 11 is positioned closer to the top of the head than the free end FE, so that the free end FE is inserted into the concha when viewed from the thickness direction Z. Based on this, the angle between the short axis direction Y and the direction in which the sagittal axis of the human body is located may be 30° to 40°. If the angle is too small, it is likely that the free end FE will not be able to be inserted into the concha, and the sound vent 112 of the sound generating unit 11 will be too far from the ear canal. If the angle is too large, it is likely that the sound generating unit 11 will not be able to be inserted into the concha, and the ear canal will be blocked by the sound generating unit 11. In other words, by installing it in this way, the sound generating unit 11 can be inserted into the concha, and the sound vent 112 of the sound generating unit 11 is at an appropriate distance from the ear canal, so that the ear canal is not blocked, and the user can hear more of the sound generated by the sound generating unit 11.

[0101] In some embodiments, the sound generating unit 11 and the ear hook 12 may both clamp the ear region corresponding to the concha from both the front and rear sides, thereby increasing the resistance of the open-type earphone 10 to falling off the ear and further improving the stability of the open-type earphone 10 when worn. For example, the free end FE of the sound generating unit 11 is pressed into the concha in the thickness direction Z. Alternatively, for example, the free end FE may abut against the concha in the long axis direction X and the short axis direction Y.

[0102] In some embodiments, both ends of the second portion 122 of the ear hook 12 may be connected to the connection end CE of the first portion 121 of the ear hook 12 and the sound generating unit 11, respectively (as shown in Figure 15). In some embodiments, the second portion 122 of the ear hook 12 may have a lowest point P and a highest point Q along the short axis Y of the sound generating unit 11. To ensure that the first decompression hole 1131 is not obstructed by the ear structure (e.g., helix or tragus) when the open-type earphone 10 is worn, the distance h1 between the center of the first decompression hole 1131 and the lowest point P in the long axis X of the sound generating unit 11 may be 5.28 mm to 7.92 mm. In some embodiments, to ensure that the earphone fits the user's ear when the user wears the open-type earphone 10, the distance h2 between the center of the first decompression hole 1131 and the highest point Q in the long axis X of the sound generating unit 11 may be 8.68 mm to 13.02 mm. In some embodiments, when a user wears open-type earphones, the distance in the longitudinal axis X of the sound generating part 11 between the center of the first pressure relief hole 1131 and any point on the second portion 122 of the ear hook 12 is in the range of 5.28 mm to 14 mm. In some embodiments, the distance in the longitudinal axis X of the sound generating part 11 between the center of the first pressure relief hole 1131 and any point on the second portion 122 of the ear hook is in the range of 5.28 mm to 13.02 mm. In some embodiments, the distance in the longitudinal axis X of the sound generating part 11 between the center of the first pressure relief hole 1131 and any point on the second portion 122 of the ear hook is in the range of 6.58 mm to 12.02 mm. In some embodiments, the distance in the longitudinal axis X of the sound generating part 11 between the center of the first pressure relief hole 1131 and any point on the second portion 122 of the ear hook is in the range of 7.58 mm to 10.02 mm. In some embodiments, the distance in the longitudinal axis X of the sound generating unit 11 between the center of the first decompression hole 1131 and any point on the second part 122 of the ear hook is in the range of 8.58 mm to 9.02 mm.

[0103] As shown in Figure 14, when a user wears the open-type earphone 10, the housing 111 of the sound generating unit 11 is positioned to be inserted at least partially into the concha 102. The cavity jointly enclosed by the inner surface IS of the sound generating unit 11 and the concha 102 can be considered as the cavity structure 41 shown in Figure 10, and the gap formed between the inner surface IS and the concha 10 (for example, a first leakage structure UC near the top of the head formed between the inner surface IS and the concha 10, and a second leakage structure LC near the ear canal formed between the inner surface IS and the ear) can be considered as the leakage structure 42 shown in Figure 10. The sound-emitting holes 112 located on the inner surface IS can be considered as point sound sources inside the cavity structure 41 shown in Figure 10, and the decompression holes 113 (e.g., the first decompression hole 1131 and the second decompression hole 1132) located on the other sides of the sound-generating unit 11 (e.g., the upper surface US and / or the lower surface LS) can be considered as point sound sources outside the cavity structure 41 shown in Figure 10. Thus, as explained in relation to Figures 10 to 13, when the open-type earphone 10 is worn in a manner in which it is at least partially inserted into the concha, that is, when worn in the manner shown in Figure 14, in terms of listening effect, most of the sound radiated from the sound-emitting holes 112 can reach the ear canal in a manner of direct or reflected light, and the volume of the sound reaching the ear canal, especially the listening volume of mid-to-low frequencies, can be significantly increased. Furthermore, only a small portion of the out-of-phase sound radiated from the depressurization holes 113 (e.g., the first depressurization hole 1131 and the second depressurization hole 1132) enters the concha cavities through the gaps (first leakage structure UC and second leakage structure LC), resulting in a weak out-of-phase cancellation effect on the sound outlet 112, thereby significantly increasing the listening volume in the ear canal. Regarding sound leakage effects, the sound outlet 112 outputs sound to the outside through the gaps and can also cancel out the sound generated by the depressurization holes 113 (e.g., the first depressurization hole 1131 and the second depressurization hole 1132) in the far field, thereby guaranteeing a sound leakage reduction effect.

[0104] In some embodiments, the first decompression hole 1131 and the second decompression hole 1132 are offset in the X direction so as not to be obstructed by the tragus. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 7 mm to 15.2 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 8 mm to 13 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 12.64 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 7.5 mm to 14 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 12 mm to 13 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O2 of the second decompression hole 1132 may be 13 mm to 15.2 mm.

[0105] In some embodiments, in order to avoid the sound output from the first depressurization port 1131 and the second depressurization port 1132 affecting the volume of the sound output from the sound outlet port 112 at the listening position, the first depressurization port 1131 and the second depressurization port 1132 should be as far away from the sound outlet port 112 as possible. For example, the center of the sound outlet port 112 may be located near the perpendicular bisector plane of the connection line between the center of the first depressurization port 1131 and the center of the second depressurization port 1132.

[0106] In some embodiments, by determining the relationship between the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 (also called the first distance) and the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 (also called the second distance), the center O of the sound emission hole 112 is located approximately on the perpendicular bisector plane of the connecting line O1O2. In some embodiments, the difference between the first distance and the second distance is less than 10%. In some embodiments, the difference between the first distance and the second distance is less than 8%. In some embodiments, the difference between the first distance and the second distance is less than 5%. In some embodiments, the difference between the first distance and the second distance is less than 2%.

[0107] In some embodiments, the distance between the first and second depressurization holes 1131 and 1132 and the sound emission hole 112 should not be too close in order to avoid the sound waves emitted by the depressurization holes (e.g., the first and second depressurization holes 1131 and 1132) and the sound waves emitted by the sound emission hole 112 canceling each other out in the near field and affecting the user's listening quality. In some embodiments, the distance between the center O1 of the first depressurization hole 1131 and the center O of the sound emission hole 112 may be 4 mm to 15 mm. In some embodiments, the distance between the center O1 of the first depressurization hole 1131 and the center O of the sound emission hole 112 may be 4 mm to 15 mm. In some embodiments, the distance between the center O1 of the first depressurization hole 1131 and the center O of the sound emission hole 112 may be 5.12 mm to 15.11 mm. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 may be 5 mm to 14 mm or more. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 may be 6 mm to 13 mm or more. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 may be 7 mm to 12 mm or more. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 may be 8 mm to 10 mm or more. In some embodiments, the distance between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112 may be 9.55 mm. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 4 mm to 16.1 mm. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 4 mm to 15 mm or more. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 5 mm to 14 mm or more. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 5.12 mm to 16.1 mm. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 6 mm to 13 mm or more.In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 7 mm to 12 mm or more. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 8 mm to 10 mm or more. In some embodiments, the distance between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 may be 9.15 mm.

[0108] In some embodiments, in order to maximize the distance between the first decompression hole 1131 and the second decompression hole 1132 and the sound emission hole 112, the angle between the connecting line O1O between the center O1 of the first decompression hole 1131 and the center O of the sound emission hole 112, and the connecting line O2O between the center O2 of the second decompression hole 1132 and the center O of the sound emission hole 112 can be reduced. In some embodiments, the angular range between the connecting line O1O and the connecting line O2O is 46.40° to 114.04°. In some embodiments, the angular range between the connecting line O1O and the connecting line O2O is 46.40° to 90.40°. In some embodiments, the angular range between the connecting line O1O and the connecting line O2O is 46.40° to 70.04°. In some embodiments, the angular range between the connecting line O1O and the connecting line O2O is 46.40° to 60.04°. In some embodiments, the angular range between the connecting line O1O2 and the connecting line O2O between the center O1 of the first depressurization hole 1131 and the center O2 of the second depressurization hole 1132 is 19.72° to 101.16°. In some embodiments, the angular range between the connecting line O1O2 and the connecting line O2O is 19.71° to 97.75°.

[0109] In some embodiments, the first depressurization port 1131 is further from the connection end CE than the second depressurization port 1132. The center of the sound vent 112 is located near or perpendicular to the perpendicular bisector plane of the connection line between the center of the first depressurization port 1131 and the center of the second depressurization port 1132, so the sound vent 112 is located in the Y direction on the side of the housing 111 that is closer to the second depressurization port 1132, rather than in an intermediate position (as shown in Figure 16). Because the sound vent 112 is positioned close to the ear canal, the second depressurization port 1132 is close to the ear canal, and the first depressurization port 1131 is farther from the ear canal. Compared to the first depressurization port 1131, sound waves emitted from the second depressurization port 1132 are more likely to cancel out in the near field with sound waves emitted from the sound vent 112. Therefore, the dimensions of the second depressurization hole 1132 may be smaller than those of the first depressurization hole 1131 in order to reduce sound leakage from the second depressurization hole 1132; that is, the area of ​​the second depressurization hole 1132 may be smaller than the area of ​​the first depressurization hole 1131. In some embodiments, it is undesirable for the difference in area between the first depressurization hole 1131 and the second depressurization hole 1132 to be too large in order to ensure that the frequency response curves of the first depressurization hole 1131 and the second depressurization hole 1132 are as close as possible and to achieve a high sound-dampening effect. In some embodiments, the ratio of the area of ​​the inner opening of the second depressurization hole 1132 to that of the first depressurization hole 1131 is 0.9 or less. In some embodiments, the ratio of the area of ​​the inner opening of the second depressurization hole 1132 to that of the first depressurization hole 1131 is 0.8 or less. In some embodiments, the ratio of the area of ​​the inner opening of the second depressurization hole 1132 to the area of ​​the first depressurization hole 1131 is 0.7 or less. In some embodiments, the ratio of the area of ​​the inner opening of the second depressurization hole 1132 to the area of ​​the first depressurization hole 1131 is 0.6 or less. In some embodiments, the ratio of the area of ​​the inner opening of the second depressurization hole 1132 to the area of ​​the first depressurization hole 1131 may be 0.55.

[0110] In some embodiments, for example in the configuration shown in Figure 14, the sound vent 112 can be brought closer to the user's ear canal in the Y direction, i.e., closer to the lower end of the sound generating unit 11, i.e., the lower side surface LS (shown in Figure 16) where the second decompression hole 1132 is located. In this case, the distance between the sound vent 112 and the first decompression hole 1131 in the Y direction is greater than the distance between the sound vent 112 and the second decompression hole 1132 in the Y direction, thereby preventing the sound waves propagated through the sound vent 112 and the first decompression hole 1131 from canceling each other out in the near field, and thus helping to increase the volume of the sound propagated through the sound vent 112 that the user can hear. Accordingly, the second depressurization hole 1132 is positioned closer to the connection end CE than the sound emission hole 112, increasing the distance between them in the X direction. This prevents the sound waves propagated through the sound emission hole 112 and the second depressurization hole 1132 from canceling each other out in the near field, thus helping to increase the volume of the sound propagated through the sound emission hole 112 that the user can hear. In some embodiments, the difference between the distance between the center O of the sound emission hole 112 and the center O1 of the first depressurization hole 1131 in the Y direction and the distance between the center O of the sound emission hole 112 and the center O2 of the second depressurization hole 1132 may be 2 mm to 10 mm, and the difference between the distance between the center O2 of the second depressurization hole 1132 and the connection end CE in the X direction and the distance between the center O of the sound emission hole 112 and the connection end CE may be 2 mm to 15 mm. In some embodiments, the difference between the distance between the center O of the sound-emitting hole 112 and the center O1 of the first decompression hole 1131 in the Y direction and the distance between the center O of the sound-emitting hole 112 and the center O2 of the second decompression hole 1132 may be 3 mm to 9 mm, and the difference between the distance between the center O2 of the second decompression hole 1132 and the connection end CE in the X direction and the distance between the center O of the sound-emitting hole 112 and the connection end CE may be 4 mm to 12 mm.In some embodiments, the difference between the distance between the center O of the sound vent 112 and the center O1 of the first depressurization hole 1131 in the Y direction and the distance between the center O of the sound vent 112 and the center O2 of the second depressurization hole 1132 may be 5 mm to 7 mm, and the difference between the distance between the center O2 of the second depressurization hole 1132 and the connection end CE in the X direction and the distance between the center O of the sound vent 112 and the connection end CE may be 6 mm to 8 mm. When the side surface of the housing 111 corresponding to the connection end CE is an arcuate surface, the distance from a certain position (for example, the center O1 of the first depressurization hole 1131 or the center O2 of the second depressurization hole 1132) to the connection end CE (or the side surface) may be the distance from that position to a tangent plane parallel to the minor axis of the connection end CE.

[0111] In some embodiments, as shown in Figures 14 and 15, the longitudinal dimension of the acoustic generating unit 11 should not be too long in order to insert the acoustic generating unit 11 at least partially into the concha. Assuming that the acoustic generating unit 11 is to be inserted at least partially into the concha, the distance from the first decompression hole 1131 and the second decompression hole 1132 to the posterior side RS of the acoustic generating unit 11 should not be too short, otherwise the area of ​​all or part of the first decompression hole 1131 and / or the second decompression hole 1132 may be shielded in the X direction by contact between the free end FE and the wall of the concha, thereby reducing the effective area of ​​the first decompression hole 1131 and / or the second decompression hole 1132. Therefore, in some embodiments, the distance a3 from the center O1 of the first decompression hole 1131 to the posterior side RS is in the range of 8.60 mm to 15.68 mm. In some embodiments, the distance a3 from the center O1 of the first decompression hole 1131 to the rear side RS is in the range of 10.44 mm to 15.68 mm. In some embodiments, the distance a3 from the center O1 of the first decompression hole 1131 to the rear side RS is in the range of 11.00 mm to 14.55 mm. In some embodiments, the distance a3 from the center O1 of the first decompression hole 1131 to the rear side RS is in the range of 12.15 mm to 13.25 mm.

[0112] Furthermore, as shown in Figure 16, in order to avoid a reduction in the effective area of ​​the first depressurization hole 1131 and / or the second depressurization hole 1132 due to shielding of all or part of the area of ​​the first depressurization hole 1131 and / or the second depressurization hole 1132 in the Z direction, the distance along the Z direction from the center O1 of the first depressurization hole 1131 to the inner surface IS of the sound generating unit 11 must not be too small. In some embodiments, the range of the distance d3 along the Z direction from the center O1 of the first depressurization hole 1131 to the inner surface IS of the sound generating unit 11 is 4.24 mm to 6.38 mm. In some embodiments, the range of the distance d3 along the Z direction from the center O1 of the first depressurization hole 1131 to the inner surface IS of the sound generating unit 11 is 4.50 mm to 5.85 mm. In some embodiments, the range of distance d3 along the Z-direction from the center O1 of the first depressurization hole 1131 to the inner surface IS of the sound generating unit 11 is 4.80 mm to 5.50 mm. In some embodiments, the range of distance d3 along the Z-direction from the center O1 of the first depressurization hole 1131 to the inner surface IS of the sound generating unit 11 is 5.20 mm to 5.55 mm.

[0113] In some embodiments, it is necessary to bring the sound vent 112 closer to the free end FE in order to improve listening efficiency by bringing the sound vent 112 closer to the ear canal. In this case, to avoid a decrease in listening volume due to the sound emitted from the second decompression vent 1132 canceling out with the sound emitted from the sound vent 112 in the ear canal (i.e., the listening position), the second decompression vent 1132 may be placed away from the rear side RS (or free end FE). Furthermore, since the first decompression vent 1131 is installed on the upper side US and is farther away from the sound vent 112 than the second decompression vent 1132, and the gap between the ear portion 100 and the inner side IS is small, the sound generated in the first decompression vent 1131 is less likely to be transmitted to the ear canal compared to the second decompression vent 1132. Therefore, in some embodiments, the distance from the center of the first decompression vent 1131 to the rear side RS may be smaller than the distance from the center of the second decompression vent 1132 to the rear side RS. In some embodiments, the distance from the center of the first decompression hole 1131 to the rear side RS may be greater than or equal to the distance from the center of the second decompression hole 1132 to the rear side RS. In some embodiments, the range of distance a4 from the center O2 of the second decompression hole 1132 to the rear side RS is 13.51 mm to 20.27 mm. In some embodiments, the range of distance a4 from the center O2 of the second decompression hole 1132 to the rear side RS is 15.00 mm to 19.55 mm. In some embodiments, the range of distance a4 from the center O2 of the second decompression hole 1132 to the rear side RS is 17.15 mm to 18.25 mm.

[0114] Furthermore, in some embodiments, the distance along the Z-direction from the center O1 of the first decompression hole 1131 to the center O2 of the second decompression hole 1132 to the inner surface IS of the sound generating unit 11 may be the same. In some embodiments, the range of the distance d4 along the Z-direction from the center O2 of the second decompression hole 1132 to the inner surface IS of the sound generating unit 11 is 4.24 mm to 6.38 mm. In some embodiments, the range of the distance d4 along the Z-direction from the center O2 of the second decompression hole 1132 to the inner surface IS of the sound generating unit 11 is 4.50 mm to 5.85 mm. In some embodiments, the range of the distance d4 along the Z-direction from the center O2 of the second decompression hole 1132 to the inner surface IS of the sound generating unit 11 is 4.80 mm to 5.50 mm. In some embodiments, the range of the distance d4 along the Z-direction from the center O2 of the second decompression hole 1132 to the inner surface IS of the sound generating unit 11 is 5.20 mm to 5.55 mm. In some embodiments, it is necessary to bring the sound vent 112 closer to the lower surface LS in order to improve listening efficiency by bringing the sound vent 112 closer to the ear canal. In this case, in order to avoid the sound emitted from the second decompression hole 1132 canceling out with the sound emitted from the sound vent 112 in the ear canal (i.e., the listening position), causing a decrease in listening volume, the second decompression hole 1132 may be further from the inner surface IS than the first decompression hole 1131 in the Z direction. That is, the distance from the center O2 of the second decompression hole 1132 to the inner surface IS may be different from the distance from the center O1 of the first decompression hole 1131 to the inner surface IS. For example, the distance from the center O1 of the first decompression hole 1131 to the inner surface IS is 2.24 mm to 5.57 mm, and the distance from the center O2 of the second decompression hole 1132 to the inner surface IS is 5.57 mm to 6.36 mm.

[0115] In some embodiments, the shape of the first depressurization holes 1131 and the second depressurization holes 1132 also affects their acoustic mass. The elongated shape of the first and second depressurization holes 1131 and 1132 results in high acoustic resistance, which reduces the intensity of the sound in the rear cavity. Therefore, to ensure the intensity of the sound output from the first and second depressurization holes 1131 and 1132, the ratio of the major axis dimension to the minor axis dimension of the first and second depressurization holes 1131 and 1132 (also called the aspect ratio of the depressurization holes 113) must not be too large. Furthermore, due to dimensional limitations in the thickness direction Z of the sound generating unit 11, the maximum dimensions of the first and second depressurization holes 1131 and 1132 in the thickness direction Z must not be too large. Therefore, when the area of ​​the depressurization holes 113 is constant, the ratio of the major axis dimension to the minor axis dimension of the first and second depressurization holes 1131 and 1132 must not be too small. In some embodiments, the shapes of the first depressurization port 1131 and the second depressurization port 1132 may include, but are not limited to, circular, elliptical, or racetrack-shaped shapes. For the sake of explanation, the following description will exemplify the case in which the first depressurization port 1131 and the second depressurization port 1132 are set to a racetrack shape.

[0116] Figure 16 is a schematic diagram of the housing of an open-type earphone according to some embodiments of the present application. As shown in Figure 16, the first pressure relief hole 1131 and the second pressure relief hole 1132 may be racetrack shaped, and both ends of the racetrack shape may be subarc-shaped or semicircular. In this case, the maximum dimension of the first pressure relief hole 1131 and the second pressure relief hole 1132 in the thickness direction Z is defined as the corresponding minor axis dimension, the minor axis dimension of the first pressure relief hole 1131 is W1, and the minor axis dimension of the second pressure relief hole 1132 is W2. The maximum dimension of the first pressure relief hole 1131 and the second pressure relief hole 1132 in the major axis direction X is defined as the corresponding major axis dimension, the major axis dimension of the first pressure relief hole 1131 is L1, and the major axis dimension of the second pressure relief hole 1132 is L2. Based on the above principle, the ratio of the major axis dimension to the minor axis dimension of the first depressurization hole 1131 and the second depressurization hole 1132 should not be too large or too small. In some embodiments, the range of the ratio of the major axis dimension L1 to the minor axis dimension W1 of the first depressurization hole 1131 may be 1 to 8. In some embodiments, the range of the ratio of the major axis dimension L1 to the minor axis dimension W1 of the first depressurization hole 1131 may be 1.33 to 8. In some embodiments, the range of the ratio of the major axis dimension L1 to the minor axis dimension W1 of the first depressurization hole 1131 may be 3 to 7. In some embodiments, the range of the ratio of the major axis dimension L1 to the minor axis dimension W1 of the first depressurization hole 1131 may be 4 to 6. In some embodiments, the ratio of the major axis dimension L2 of the second depressurization hole 1132 to the minor axis dimension W2 of the second depressurization hole 1132 may be in the range of 1 to 8. In some embodiments, the ratio of the major axis dimension L2 of the second depressurization hole 1132 to the minor axis dimension W2 of the second depressurization hole 1132 may be in the range of 3 to 7. In some embodiments, the ratio of the major axis dimension L2 of the second depressurization hole 1132 to the minor axis dimension W2 of the second depressurization hole 1132 may be in the range of 4 to 6. In some embodiments, the ratio of the major axis dimension L2 of the second depressurization hole 1132 to the minor axis dimension W2 of the second depressurization hole 1132 may be in the range of 1 to 6.

[0117] In some embodiments, when both the first pressure relief port 1131 and the second pressure relief port 1132 use a straight cylindrical structure, that is, when the dimensions of their corresponding inner and outer openings are the same, the range of the major axis dimension L1 of the first pressure relief port 1131 may be 1.43 mm to 16.38 mm, and the range of the minor axis dimension W1 may be 1.43 mm to 5.7 mm. In some embodiments, the range of the major axis dimension L1 of the first pressure relief port 1131 may be 4.10 mm to 16.38 mm, and the range of the minor axis dimension W1 may be 1.43 mm to 5.7 mm. In some embodiments, the range of the major axis dimension L1 of the first pressure relief port 1131 may be 6.14 mm to 10.92 mm, and the range of the minor axis dimension W1 may be 2.14 mm to 3.80 mm. In some embodiments, the range of the major axis dimension L2 of the second pressure relief hole 1132 may be 1.00 mm to 10.38 mm, and the range of the minor axis dimension W2 may be 1.00 mm to 4.05 mm. In some embodiments, the range of the major axis dimension L2 of the second pressure relief hole 1132 may be 2.59 mm to 10.38 mm, and the range of the minor axis dimension W2 may be 1.52 mm to 4.05 mm. In some embodiments, the range of the major axis dimension L2 of the second pressure relief hole 1132 may be 3.89 mm to 6.92 mm, and the range of the minor axis dimension W2 may be 2.28 mm to 4.05 mm.

[0118] In some embodiments, to facilitate processing and manufacturing and reduce the difficulty of the process, both the first depressurization port 1131 and the second depressurization port 1132 may have a trumpet-shaped structure, for example, the area of ​​the inner opening may be smaller than the area of ​​the corresponding outer opening, or the area of ​​the outer opening may be smaller than the area of ​​the corresponding inner opening.

[0119] In some embodiments, when both the first decompression hole 1131 and the second decompression hole 1132 use a trumpet-shaped structure, the range of the value of the major axis dimension along the X direction of the outer opening of the first decompression hole 1131 may be 4.10 mm to 16.38 mm, and the range of the value of the minor axis dimension along the Z direction of the outer opening of the first decompression hole 1131 may be 1.43 mm to 5.7 mm. The range of the value of the outer opening area of the first decompression hole 1131 is 5.39 mm 2 ~86.21 mm 2 And the range of the value of the major axis dimension along the X direction of the inner opening of the first decompression hole 1131 may be 3.92 mm to 15.68 mm, and the range of the value of the minor axis dimension along the Z direction of the inner opening of the first decompression hole 1131 may be 1.29 mm to 5.14 mm. The range of the value of the inner opening area of the first decompression hole 1131 is 4.58 mm 2 ~73.32 mm 2 And the range of the value of the major axis dimension along the X direction of the outer opening of the second decompression hole 1132 may be 2.59 mm to 10.38 mm, and the range of the value of the minor axis dimension along the Z direction of the outer opening of the second decompression hole 1132 may be 1.52 mm to 4.05 mm. The range of the value of the outer opening area of the second decompression hole 1132 is 3.42 mm 2 ~54.68 mm 2 And the range of the value of the major axis dimension along the X direction of the inner opening of the second decompression hole 1132 may be 2.28 mm to 9.1 mm, and the range of the value of the minor axis dimension along the Z direction of the inner opening of the second decompression hole 1132 may be 1.26 mm to 5.04 mm. The range of the value of the inner opening area of the second decompression hole 1132 is 2.56 mm 2 ~40.90 mm 2 That is. In some embodiments, when both the first decompression hole 1131 and the second decompression hole 1132 use a trumpet-shaped structure, the range of the value of the major axis dimension along the X direction of the outer opening of the first decompression hole 1131 may be 6.14 mm to 10.92 mm, and the range of the value of the minor axis dimension along the Z direction of the outer opening of the first decompression hole 1131 may be 2.14 mm to 3.80 mm. The range of the value of the outer opening area of the first decompression hole 1131 is 12.12 mm 2 ~38.32 mm 2The range of values ​​for the major axis dimension along the X direction of the inner opening of the first decompression hole 1131 may be 5.88 mm to 10.45 mm, the range of values ​​for the minor axis dimension along the Z direction of the inner opening of the first decompression hole 1131 may be 1.93 mm to 3.43 mm, and the range of values ​​for the inner opening area of ​​the first decompression hole 1131 may be 10.31 mm. 2 ~32.59mm 2 The range of values ​​for the major axis dimension along the X direction of the outer opening of the second decompression hole 1132 may be 3.89 mm to 6.92 mm, the range of values ​​for the minor axis dimension along the Z direction of the outer opening of the second decompression hole 1132 may be 2.28 mm to 4.05 mm, and the range of values ​​for the outer opening area of ​​the second decompression hole 1132 may be 7.69 mm. 2 ~24.30mm 2 The range of values ​​for the major axis dimension along the X direction of the inner opening of the second decompression hole 1132 may be 3.41 mm to 6.61 mm, the range of values ​​for the minor axis dimension along the Z direction of the inner opening of the second decompression hole 1132 may be 1.89 mm to 3.36 mm, and the range of values ​​for the inner opening area of ​​the second decompression hole 1132 may be 5.75 mm. 2 ~18.18mm 2 In some embodiments, when both the first decompression hole 1131 and the second decompression hole 1132 use a trumpet-shaped structure, the value of the major axis dimension along the X direction of the outer opening of the first decompression hole 1131 may be 8.19 mm, the value of the minor axis dimension along the Z direction of the outer opening of the first decompression hole 1131 may be 2.85 mm, and the value of the outer opening area of ​​the first decompression hole 1131 may be 21.55 mm. 2 The value of the major axis dimension along the X direction of the inner opening of the first decompression hole 1131 may be 7.84 mm, the value of the minor axis dimension along the Z direction of the inner opening of the first decompression hole 1131 may be 2.57 mm, and the value of the inner opening area of ​​the first decompression hole 1131 may be 18.33 mm 2 The value of the major axis dimension along the X direction of the outer opening of the second decompression hole 1132 may be 5.19 mm, the value of the minor axis dimension along the Z direction of the outer opening of the second decompression hole 1132 may be 3.04 mm, and the value of the outer opening area of ​​the second decompression hole 1132 may be 13.67 mm 2The value of the major axis dimension along the X direction of the inner opening of the second decompression hole 1132 may be 4.55 mm, the value of the minor axis dimension along the Z direction of the inner opening of the second decompression hole 1132 may be 2.52 mm, and the value of the inner opening area of ​​the second decompression hole 1132 may be 10.23 mm 2 That is the case.

[0120] In some embodiments, the ratio of the area of ​​the inner opening of the first decompression hole 1131 to the area of ​​the sound vent 112 may be 0.1 to 15. In some embodiments, the ratio of the area of ​​the inner opening of the second decompression hole 1132 to the area of ​​the sound vent 112 may be 0.1 to 3. In some embodiments, the ratio of the area of ​​the inner opening of the first decompression hole 1131 to the area of ​​the sound vent 112 may be 0.2 to 10. In some embodiments, the ratio of the area of ​​the inner opening of the second decompression hole 1132 to the area of ​​the sound vent 112 may be 0.1 to 2. In some embodiments, the ratio of the area of ​​the inner opening of the first decompression hole 1131 to the area of ​​the sound vent 112 may be 0.3 to 5. In some embodiments, the ratio of the area of ​​the inner opening of the second decompression hole 1132 to the area of ​​the sound vent 112 may be 0.2 to 1.

[0121] In some embodiments, when the first depressurization holes 1131 and the second depressurization holes 1132 form a Helmholtz resonant cavity model together with the rear cavity 115 as acoustic holes, as can be seen from equation (2) described later, the larger the area of ​​the first depressurization holes 1131 and the second depressurization holes 1132, the larger the resonant frequency of the rear cavity 115. This shifts the resonant frequency of the corresponding sound leakage to the highest possible frequency band (e.g., a frequency range greater than 4 kHz), which helps to improve the flat region in the frequency response curve and helps to prevent sound leakage.

[0122] Figure 17 is a frequency response curve diagram of an open-type earphone corresponding to a first pressure relief port of a different area, according to some embodiments of the present application. Figure 18 is a frequency response curve diagram of an open-type earphone corresponding to a second pressure relief port of a different area, according to some embodiments of the present application.

[0123] As shown in Figure 17, curves 171, 172, 173, 174, and 175 have areas of 0 and 2.52 mm², respectively. 2 5.52mm 2 8.52mm 2 and 11.52mm 2 This represents the frequency response curve corresponding to the first depressurization hole 1131. As shown in Figure 18, curves 181, 182, 183, 184, and 185 have areas of 0 and 4.02 mm², respectively. 2 5.52mm 2 7.02mm 2 and 8.52mm 2 This represents the frequency response curve corresponding to the second depressurization hole 1132.

[0124] As can be seen from Figure 17, when other structures (e.g., sound emission holes 112, second pressure relief holes 1132, etc.) are fixed, as the area of ​​the first pressure relief hole 1131 gradually increases, the resonant frequency corresponding to the rear cavity in the frequency response curve of the open-type earphone 10 (i.e., the frequency corresponding to the resonant peak at the dashed circle G1) gradually shifts to a higher frequency, and the flat region of the frequency response curve widens. 2 As the area increases, the shift in the resonant frequency corresponding to the rear cavity to higher frequencies becomes more gradual. Note that the frequency response curve in Figure 17 is the frequency response curve at a point 15 mm directly in front of the center O of the sound vent, obtained by simulation under the condition that the position and dimensions of the second depressurization hole 1132 do not change. Similarly, as can be seen from Figure 18, when other structures (e.g., the sound vent 112, the first depressurization hole 1131, etc.) are fixed, as the area of ​​the second depressurization hole 1132 gradually increases, the resonant frequency corresponding to the rear cavity in the frequency response curve of the open-type earphone 10 (i.e., the frequency corresponding to the resonant peak at the dashed circle G2) gradually shifts to higher frequencies, and the flat region of the frequency response curve widens. Note that the frequency response curve in Figure 18 is the frequency response curve at a point 15 mm directly in front of the center O of the sound vent, obtained by simulation under the condition that the position and dimensions of the first depressurization hole 1131 do not change.

[0125] In some embodiments, the area of ​​the first pressure relief hole 1131 and / or the second pressure relief hole 1132 must not be too small in order to ensure a wide flat region (e.g., the region before the resonance peak) in the frequency response curve of the open-type earphone, to obtain a better sound leakage reduction effect in the mid-to-high frequency range (e.g., 2kHz to 6kHz), and to ensure that the high-pressure region of the sound field in the rear cavity is destroyed, and that the intensity of the sound generated in the rear cavity is sufficient in the far field. Furthermore, in actual applications, if the area of ​​the first pressure relief hole 1131 and / or the second pressure relief hole 1132 is too large, it will have a certain effect on other aspects of the open-type earphone 10 such as appearance, structural strength, waterproofing, and dustproofing. In some embodiments, the area of ​​the first pressure relief hole 1131 and / or the second pressure relief hole 1132 is 3.78 mm². 2 ~86.21mm 2 Therefore, the area range of the second decompression hole 1132 is 2.78 mm². 2 ~54.68mm 2 In some embodiments, the area range of the first pressure relief hole 1131 is 3.78 mm. 2 ~22.07mm 2 Therefore, the area range of the second decompression hole 1132 is 2.78 mm². 2 ~16.07mm 2 In some embodiments, the area range of the first pressure relief hole 1131 is 6.78 mm. 2 ~20.07mm 2 Therefore, the area range of the second decompression hole 1132 is 4.78 mm². 2 ~13.07mm 2 That is the case.

[0126] In some embodiments, the decompression holes 113 (including the first decompression hole 1131 and the second decompression hole 1132) and the rear cavity installed in the housing 111 can be considered as a Helmholtz resonant cavity model. Therefore, the size of the openings of the first decompression hole 1131 and the second decompression hole 1132 affects the resonant frequency of the rear cavity. To ensure that the resonant frequency of the rear cavity is at a high frequency, for example, within the frequency range of 2000 Hz to 6000 Hz, this can be achieved by designing a range of ratios between the size of the openings of the first decompression hole 1131 and the second decompression hole 1132 and the volume of the rear cavity. In some embodiments, the dimensions of the acoustic generating unit 11 along the Y direction may be determined based on the dimensions of the concha cavities so that when the acoustic generating unit 11 is at least partially inserted into the concha cavities, it can form with the concha cavities the first and / or second leak structures described elsewhere in this application. In this case, when the distance from the sound emission hole 112 to the bottom surface of the transducer (for example, the bottom surface of the magnetic circuit assembly 1164 of the transducer 116 in Figure 20A) is constant, the volume of the rear cavity may be related to the area of ​​the upper surface US and / or lower surface LS of the sound generating section 11. In order to make the resonant frequency of the rear cavity sufficiently high, the ratio of the area of ​​the decompression hole 113 to the volume of the rear cavity must not be too small; in other words, the ratio of the area of ​​the decompression hole 113 to the area of ​​the upper surface US and / or lower surface LS must not be too small. Also, in order to ensure the service life of the open-type earphone 10 by ensuring the stability of the physical structure of the housing 111, the ratio of the area of ​​the decompression hole 113 to the area of ​​the upper surface US and / or lower surface LS must not be too large. In some embodiments, the ratio of the area of ​​the first decompression hole 1131 to the area of ​​the upper surface US is 0.036 to 0.093, and the ratio of the area of ​​the second decompression hole 1132 to the area of ​​the lower surface LS is 0.018 to 0.051. In some embodiments, the ratio of the area of ​​the first decompression hole 1131 to the area of ​​the upper surface US is 0.046 to 0.083, and the ratio of the area of ​​the second decompression hole 1132 to the area of ​​the lower surface LS is 0.028 to 0.041.In some embodiments, the ratio of the area of ​​the first decompression hole 1131 to the area of ​​the upper surface US is 0.056 to 0.073, and the ratio of the area of ​​the second decompression hole 1132 to the area of ​​the lower surface LS is 0.031 to 0.038. In some embodiments, the ratio of the area of ​​the first decompression hole 1131 to the area of ​​the upper surface US is 0.061 to 0.068, and the ratio of the area of ​​the second decompression hole 1132 to the area of ​​the lower surface LS is 0.033 to 0.036.

[0127] Figure 19 is a schematic projection onto the sagittal plane of an open-type earphone according to several embodiments of the present application when it is being worn.

[0128] In some embodiments, as shown in Figures 14 and 19, the free end FE can abut the concha in the longitudinal axis X and the minor axis Y in order to stably attach the sound generating unit 11 to the user's ear, easily form a cavity structure as shown in Figure 10, and install at least two leakage structures in the cavity structure. At this time, the inner surface IS of the sound generating unit 11 is inclined with respect to the sagittal plane, and at this time, at least a first leakage structure UC close to the top of the head (i.e., a gap formed between the concha and the upper boundary of the inner surface IS) and a second leakage structure LC close to the ear canal (i.e., a gap formed between the concha and the lower boundary of the inner surface IS) are installed between the inner surface IS of the sound generating unit and the concha. This increases the listening volume, especially the mid-low frequency listening volume, while still retaining the effect of canceling out far-field sound leakage, thereby improving the acoustic output performance of the open-type earphone 10.

[0129] In some embodiments, when the open-type earphone 10 is worn in the manner shown in Figure 14, the first leakage structure UC and the second leakage structure LC formed between the inner surface IS of the sound generating part and the concha cavity have a constant scale in both the longitudinal axis X and the thickness direction Z. In some embodiments, in order to easily understand the positions of the first leakage structure UC and the second leakage structure LC, when the open-type earphone 10 is worn, the midpoint of two points formed when the upper / lower boundary of the inner surface IS intersects with the ear portion (e.g., the side wall of the concha cavity, the crus of the helix), may be used as the reference point for the position of the first leakage structure UC and the second leakage structure LC, and the center of the ear canal opening may be used as the reference point for the position of the ear canal. In some embodiments, to facilitate understanding of the positions of the first leak structure UC and the second leak structure LC, when the open-type earphone 10 is in the wearing state, the midpoint of the upper boundary of the inner surface IS may be used as the reference point for the position of the first leak structure UC, and a point that divides the lower boundary of the inner surface IS into three equal parts (hereinafter abbreviated as the 1 / 3 point of the lower boundary of the inner surface IS) close to the free end FE may be used as the reference point for the position of the second leak structure LC. In this specification, if the boundary between the inner surface IS and the upper surface US and / or lower surface LS is arc-shaped, the upper boundary of the inner surface IS may be the intersection line of the inner surface IS and the upper surface US, and the lower boundary of the inner surface IS may be the intersection line of the inner surface IS and the lower surface LS. In some embodiments, if one or more sides of the sound generating section 11 (e.g., the inner surface IS, the upper surface US and / or lower surface LS) are arc-shaped, the intersection line of the two sides may be the intersection line between the tangent planes of the two sides that are furthest from the center of the sound generating section and parallel to the major or minor axis of the sound generating section.

[0130] As merely an example, in this specification, the midpoint of the upper boundary and the 1 / 3 point of the lower boundary of the inner surface IS are used as reference points for the position of the first leak structure UC and the second leak structure LC, respectively. Note that the selected midpoint of the upper boundary and the 1 / 3 point of the lower boundary of the inner surface IS are used only as exemplary reference points to explain the positions of the first leak structure UC and the second leak structure LC. In some embodiments, other reference points may be selected to explain the positions of the first leak structure UC and the second leak structure LC. For example, due to differences in the ear shape of different users, the first leak structure UC / second leak structure LC formed when the open-type earphone 10 is worn is a gap whose width gradually changes, in which case the reference position of the first leak structure UC / second leak structure LC may be a position close to the region where the width of the gap at the upper / lower boundary of the inner surface IS is maximum. For example, the 1 / 3 point close to the free end FE of the upper boundary of the inner surface IS may be the position of the first leak structure UC, and the midpoint of the lower boundary of the inner surface IS may be the position of the second leak structure LC.

[0131] In some embodiments, as shown in Figure 19, the projection of the upper boundary of the inner surface IS onto the sagittal plane may coincide with the projection of the upper surface US onto the sagittal plane, and the projection of the lower boundary of the inner surface IS onto the sagittal plane may coincide with the projection of the lower surface LS onto the sagittal plane. Point A is the projection of the position reference point of the first leak structure UC (i.e., the midpoint of the upper boundary of the inner surface IS) onto the sagittal plane, and point B is the projection of the position reference point of the second leak structure LC (i.e., the 1 / 3 point of the lower boundary of the inner surface IS) onto the sagittal plane, and "projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane" may be the projection point projected onto the sagittal plane of the intersection of the upper boundary of the inner surface IS and the short-axis center plane of the transducer's magnetic circuit assembly (e.g., the magnetic circuit assembly 1144 described later). The short-axis center plane of the magnetic circuit assembly is a plane parallel to the short axis direction of the sound generating unit 11 and passing through the geometric center of the magnetic circuit assembly. "The projection point B onto the sagittal plane of the 1 / 3 point of the lower boundary of the inner surface IS" may also be the projection point onto the sagittal plane of the trisection point adjacent to the free end FE of the lower boundary of the inner surface IS.

[0132] As shown in Figure 19, in some embodiments, when worn, the projection of the sound generating section 11 of the open-type earphone 10 onto the sagittal plane can at least partially cover the user's ear canal, but the ear canal can communicate with the outside through the concha, thereby achieving freedom of both ears for the user. In some embodiments, the sound from the decompression hole 113 can be transmitted to the cavity structure via a leak structure (e.g., a first leak structure UC or a second leak structure LC) and canceled out with the sound from the sound emission hole 112, so the first decompression hole 1131 and the second decompression hole 1132 should not be too close to the upper and lower leak structures.

[0133] In some embodiments, the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane and the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane may substantially overlap. In some embodiments, the range of distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane is 2 mm or less. In some embodiments, the range of distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane is 1 mm or less. In some embodiments, the range of distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane is 0.5 mm or less.

[0134] If the relative position between the sound vent 112 and the first pressure relief vent 1131 does not change (i.e., the distance between the center O of the sound vent 112 and the center O1 of the first pressure relief vent 1131 does not change), the larger the volume V of the cavity structure, the smaller the listening index of the open-type earphone 10 as a whole (across the entire frequency band). This is because, due to the influence of air sound resonance within the cavity structure, air sound resonance occurs within the cavity structure at the resonant frequency of the cavity structure, radiating sound much louder outward than that from the pressure relief vent 113, significantly increasing sound leakage, and furthermore, the listening index becomes noticeably smaller around the resonant frequency.

[0135] In some embodiments, the greater the distance from the projection point O2' of the center O2 of the second decompression hole 1132 onto the sagittal plane to the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane, the greater the volume V of the cavity structure. Therefore, in some embodiments, assuming that the sound generating unit 11 is inserted at least partially into the concha, the range of the distance from point O2' to point A is 14.4 mm to 21.6 mm in order to appropriately set the volume V of the cavity structure to enhance the sound collection effect of the ear canal. In some embodiments, the range of the distance from point O2' to point A is 16.4 mm to 19.6 mm. In some embodiments, the range of the distance from point O2' to point A is 17.4 mm to 18.6 mm. In some embodiments, the range of the distance from point O2' to point A is 17.8 mm to 18.2 mm.

[0136] In some embodiments, the sound generating unit 11 is inserted into the concha cavity, and in order to ensure that there is an appropriate gap (forming an opening for the cavity structure) between the upper boundary of the inner surface IS and the concha cavity, the distance range from the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 12 mm to 18 mm, and the distance range from the projection point O2' of the center O2 of the second decompression hole onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 6.88 mm to 10.32 mm. In some embodiments, the distance range from the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 14 mm to 16 mm, and the distance range from the projection point O2' of the center O2 of the second decompression hole onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 7.88 mm to 9.32 mm. In some embodiments, the distance range from the projection point A of the midpoint of the upper boundary of the inner surface IS onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 14.5 mm to 15.5 mm, and the distance range from the projection point O2' of the center O2 of the second decompression hole onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 7.88 mm to 8.32 mm.

[0137] In some embodiments, the acoustic generating unit 11 is inserted into the concha cavity, and in order to ensure that there is an appropriate gap (forming an opening for the cavity structure) between the upper boundary of the inner surface IS and the concha cavity, the distance range from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 12 mm to 18 mm. In some embodiments, the distance range from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 14 mm to 16 mm. In some embodiments, the distance range from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 14.5 mm to 15.5 mm.

[0138] In some embodiments, the greater the distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane, the greater the volume V of the cavity structure. Therefore, in some embodiments, assuming that the sound generating unit 11 is at least partially inserted into the concha cavity, the range of the distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 13.76 mm to 20.64 mm in order to appropriately adjust the volume V of the cavity structure to enhance the sound collection effect of the ear canal. In some embodiments, the range of the distance from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 15.76 mm to 18.64 mm. In some embodiments, the distance range from the projection point O1' of the center O1 of the first decompression hole 1131 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 16.16 mm to 18.24 mm.

[0139] In some embodiments, to reduce the transmission of sound from the second decompression hole 1132 to the cavity structure via the second leakage structure LC and its cancellation with the sound from the sound emission hole 112, the distance range from the projection point O2' of the center O2 of the second decompression hole 1132 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 8.16 mm to 12.24 mm. In some embodiments, the distance range from the projection point O2' of the center O2 of the second decompression hole 1132 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 9.16 mm to 11.24 mm. In some embodiments, the distance range from the projection point O2' of the center O2 of the second decompression hole 1132 onto the sagittal plane to the projection point B of the 1 / 3 point of the lower boundary of the inner surface IS onto the sagittal plane is 9.66 mm to 10.74 mm.

[0140] In some embodiments, the sound generating unit 11 is inserted into the concha cavity, and in order to ensure that there is an appropriate gap (forming an opening for the cavity structure) between the upper boundary of the inner surface IS and the concha cavity, the distance range from the projection B of the 1 / 3 point on the lower boundary of the inner surface onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 1.76 mm to 2.64 mm. In some embodiments, the distance range from the projection B of the 1 / 3 point on the lower boundary of the inner surface onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 1.96 mm to 2.44 mm. In some embodiments, the distance range from the projection B of the 1 / 3 point on the lower boundary of the inner surface onto the sagittal plane to the projection point O3' of the center O3 of the ear canal opening onto the sagittal plane is 2.16 mm to 2.24 mm.

[0141] Figure 20A is an illustrative internal diagram of an acoustic generating unit according to several embodiments of the present application.

[0142] As shown in Figure 20A, the sound generating unit 11 may include a housing 111 connected to the ear hook 12 and a transducer 116 installed inside the housing 111. In some embodiments, the sound generating unit 11 may further include a main control circuit board 13 installed inside the housing 111 and a battery (not shown) installed at one end of the ear hook 12 away from the sound generating unit 11, with the battery and transducer 116 each electrically connected to the main control circuit board 13, and the battery being able to supply power to the transducer 116 under the control of the main control circuit board 13. Naturally, both the battery and transducer 116 may be installed inside the sound generating unit 11, and the battery may be closer at its connection end CE, while the transducer 116 may be closer at its free end FE.

[0143] In some embodiments, the open-type earphone 10 may include an adjustment mechanism connecting the sound generating unit 11 and the ear hook 12, allowing different users to adjust the relative position of the sound generating unit 11 in the ear using the adjustment mechanism while wearing the earphone, thereby positioning the sound generating unit 11 in an appropriate location, thereby forming a cavity structure between the sound generating unit 11 and the concha. In addition, the presence of the adjustment mechanism also allows the user to adjust the earphone 10 to a more stable and comfortable position.

[0144] Because the concha cavities have a certain volume and depth, after the free end FE is inserted into the concha cavities, a certain distance can be maintained between the inner surface IS of the sound generating unit 11 and the concha cavities. In other words, when worn, the sound generating unit 11 can work in cooperation with the concha cavities to form a cavity structure that communicates with the external auditory canal, and a sound vent 112 can be installed in the sound generating unit 11 (e.g., the inner surface IS), and the sound vent 112 can be located at least partially within the cavity structure. In this way, when worn, the sound waves propagated from the sound vent 112 are restricted by the cavity structure, that is, the cavity structure can focus the sound waves and propagate them better into the external auditory canal, thereby improving the volume and sound quality of the sound heard by the user in the near field, and thus contributing to the improvement of the acoustic effect of the earphones 10. Furthermore, since the sound generating unit 11 may be installed so as not to block the external auditory canal when worn, the cavity structure may be installed in a semi-open type. Thus, sound waves propagated from the sound emission holes 112 are partially transmitted to the ear canal, allowing the user to hear the sound, while the remaining portion, along with the sound reflected in the ear canal, propagates to the outside of the earphone 10 and the ear through the gap between the sound generating unit 11 and the ear (for example, the part of the concha not covered by the sound generating unit 11), thereby forming a first sound leakage in the far field. At the same time, sound waves propagated through the depressurization holes 113 formed in the sound generating unit 11 (for example, the first depressurization hole 1131 and the second depressurization hole 1132) generally form a second sound leakage in the far field. Since the intensity of the first sound leakage and the intensity of the second sound leakage are equal, and the phases of the first sound leakage and the phases of the second sound leakage are (substantially) out of phase with each other, they can cancel each other out in the far field, thus helping to reduce sound leakage in the far field of the open-type earphone 10.

[0145] In some embodiments, a front cavity 114 may be formed between the transducer 116 and the housing 111, and the sound vents 112 are located in a region of the housing 111 surrounding the front cavity 114, and the front cavity 114 communicates with the outside through the sound vents 112.

[0146] In some embodiments, the front cavity 114 is located between the diaphragm of the transducer 116 and the housing 111, and the front cavity 114 may have a large depth dimension (i.e., the distance dimension between the diaphragm of the transducer 116 and the housing 111 facing it) to ensure that the diaphragm has sufficient vibration space. In some embodiments, as shown in Figure 20A, the sound emission hole 112 is located on the inner surface IS in the thickness direction Z, in which case the depth of the front cavity 114 may be the dimension of the front cavity 114 in the Z direction. However, if the depth of the front cavity 114 is too large, the dimensions of the sound generating part 11 will increase, affecting the wearing comfort of the open-type earphone 10. In some embodiments, the depth of the front cavity 114 may be 0.55 mm to 1.00 mm. In some embodiments, the depth of the front cavity 114 may be 0.66 mm to 0.99 mm. In some embodiments, the depth of the front cavity 114 may be 0.76 mm to 0.99 mm. In some embodiments, the depth of the front cavity 114 may be 0.96 mm to 0.99 mm. In some embodiments, the depth of the front cavity 114 may be 0.97 mm.

[0147] To improve the sound emission effect of the open-type earphone 10, the overall frequency response curve of the sound generating section has a wide flat region by making the resonant frequency of a structure such as a Helmholtz resonant cavity consisting of a front cavity 114 and a sound emission hole 112 as high as possible. In some embodiments, the resonant frequency f1 of the front cavity 114 may be 3 kHz or higher. In some embodiments, the resonant frequency f1 of the front cavity 114 may be 4 kHz or higher. In some embodiments, the resonant frequency of the front cavity 114 may be 6 kHz or higher. In some embodiments, the resonant frequency of the front cavity 114 may be 7 kHz or higher. In some embodiments, the resonant frequency of the front cavity 114 may be 8 kHz or higher.

[0148] As shown in Figure 20A, in some embodiments, an acoustic resistance mesh 118 may be installed at a position corresponding to the first depressurization hole 1131 and / or the second depressurization hole 1132. The acoustic resistance mesh 118 can adjust the amplitude at the resonant frequency of the rear cavity and can also provide dustproof and waterproof effects. When other parameters of the acoustic resistance mesh 118 are constant, the magnitude of its acoustic resistance is related to its thickness, and acoustic resistance meshes of different thicknesses have a certain effect on the acoustic output performance of the corresponding acoustic holes. Therefore, there are certain limitations on the thickness of the acoustic resistance mesh 118. In some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first depressurization hole 1131 and the second depressurization hole 1132 may be 35 μm to 300 μm. In some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first depressurization hole 1131 and the second depressurization hole 1132 may be 40 μm to 150 μm. In some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first depressurization hole 1131 and the second depressurization hole 1132 may be 50 μm to 65 μm. In some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first depressurization hole 1131 and the second depressurization hole 1132 may be 55 μm to 62 μm. On the other hand, the greater the distance between the end of the acoustic resistance mesh 118 facing outward from the housing 111 (i.e., the upper surface of the acoustic resistance mesh 118) and the outer surface of the housing 111, the closer the installation position of the corresponding acoustic resistance mesh 118 becomes to the rear cavity, and the smaller the volume of the rear cavity becomes. In some embodiments, the distance between the upper surface of the acoustic resistance mesh 118 installed in the first pressure relief hole 1131 and the outer surface of the housing 1111 may be 0.8 mm to 0.9 mm, and the distance between the upper surface of the acoustic resistance mesh 118 installed in the second pressure relief hole 1132 and the outer surface of the housing 1111 may be 0.7 mm to 0.8 mm.In some embodiments, the distance between the upper surface of the acoustic resistance mesh 118 installed in the first pressure relief hole 1131 and the outer surface of the housing 1111 may be 0.82 mm to 0.88 mm, and the distance between the upper surface of the acoustic resistance mesh 118 installed in the second pressure relief hole 1132 and the outer surface of the housing 1111 may be 0.72 mm to 0.76 mm. In some embodiments, the distance between the upper surface of the acoustic resistance mesh 118 installed in the first pressure relief hole 1131 and the outer surface of the housing 1111 may be 0.86 mm, and the distance between the upper surface of the acoustic resistance mesh 118 installed in the second pressure relief hole 1132 and the outer surface of the housing 1111 may be 0.73 mm.

[0149] Figure 20B is an illustrative diagram of a second acoustic cavity according to some embodiments of this specification.

[0150] As shown in Figures 20A and 20B, in some embodiments, the bracket 117 may be installed within the housing 111, and a cavity 115 may be formed between the bracket 117 and the transducer 116, thereby separating the cavity 115 from other structures within the housing 111 (e.g., the main control circuit board 13), and thus helping to improve the acoustic expressiveness of the sound generating unit 11. Note that the rear cavity described elsewhere in this specification may include not only the cavity 115 but also other regions located behind the diaphragm and communicating with the cavity 115 (e.g., the space located between the diaphragm and the magnetic circuit assembly). By providing a depressurization hole 113 (for example, a first depressurization hole 1131 and / or a second depressurization hole 1132) in the housing 111, and an acoustic passage connecting the depressurization hole 113 and the cavity 115 in the bracket 117, the cavity 115 is in communication with the external environment, that is, air can freely enter and exit the rear cavity, which helps to reduce resistance in the vibration process of the diaphragm of the transducer 116.

[0151] In some embodiments, the resonant frequency of the rear cavity may be set high because the frequency response curve of the rear cavity needs to have a wide flat region for the acoustic output performance of the open-type earphone 10. Furthermore, in some embodiments, the resonant frequency of the rear cavity may be equal to the resonant frequency of the front cavity 114 in order to better cancel out the second sound leakage formed by the depressurization hole 113 with the first sound leakage. In some embodiments, the difference between the resonant frequency of the rear cavity and the resonant frequency of the front cavity 114 may be 1 kHz or less. In some embodiments, the difference between the resonant frequency of the rear cavity and the resonant frequency of the front cavity 114 may be 500 Hz or less. In some embodiments, the difference between the resonant frequency of the rear cavity and the resonant frequency of the front cavity 114 may be 200 Hz or less. In some embodiments, the resonant frequency of the rear cavity may be 4.5 kHz or higher. In some embodiments, the resonant frequency of the rear cavity may be 6 kHz or higher. In some embodiments, the resonant frequency of the rear cavity may be 8 kHz.

[0152] In some embodiments, the combination of a rear cavity and a depressurization hole 113 located in the housing 111 can be considered a Helmholtz resonant cavity model. The rear cavity can be the cavity of the Helmholtz resonant cavity model, and the depressurization hole can be the neck of the Helmholtz resonant cavity model, in which case the resonant frequency of the Helmholtz resonant cavity model is the resonant frequency of the rear cavity. In the Helmholtz resonant cavity model, the dimensions of the neck (e.g., the first depressurization hole 1131 or the second depressurization hole 1132) can affect the resonant frequency f of the cavity (e.g., the rear cavity), and the specific relationship is shown in equation (2).

[0153]

number

[0154] Here, c represents the speed of sound, S represents the area of ​​the neck (e.g., the first decompression hole 1131 or the second decompression hole 1132), V represents the volume of the cavity (e.g., the rear cavity), and L represents the depth of the neck (e.g., the first decompression hole 1131 or the second decompression hole 1132).

[0155] As can be seen from equation (2), as the volume V of the rear cavity decreases, the resonant frequency f2 of the rear cavity increases. Therefore, in order to make the resonant frequency of the rear cavity sufficiently large, the volume of the rear cavity must be sufficiently small.

[0156] However, the volume of the rear cavity also affects its acoustic capacitance Ca, and a change in the acoustic capacitance Ca of the rear cavity alters its capacitive reactance characteristics, which in turn affects its vibration characteristics. The specific relationship between the volume of the rear cavity and its acoustic capacitance Ca is shown in equation (3).

[0157]

number

[0158] Here, ρ represents the air density, c represents the speed of sound, and V represents the volume of the rear cavity.

[0159] As can be seen from equations (2) and (3), as the volume V of the rear cavity increases, the acoustic capacitance Ca of the rear cavity increases, but the corresponding resonant frequency of the rear cavity decreases. In order to increase both the resonant frequency and the acoustic capacitance Ca of the rear cavity, it is necessary to appropriately set the range of values ​​for the volume V of the rear cavity.

[0160] As shown in Figure 20B, in some embodiments, the cross-section of the cavity 115 may consist of two vertical sides and one curved side, and by connecting the two endpoints of the curved side, the cross-section (e.g., cross-section C1C2C3) can be considered to be approximately triangular. The hypotenuse C1C3 is composed of a connection line between the curved surface formed on the bracket 117 and the two endpoints formed by the contact of the two straight sides, and the two straight sides C1C2 and C2C3 are composed of the frame of the transducer 116, with an angle α between the hypotenuse C1C3 and the straight side C2C3. In some embodiments, the frame of the sound generating unit 11 needs to have an acoustic hole (e.g., a sound passage hole) in the region where the straight side C2C3 is located, so that the sound generated by the vibration of the diaphragm 1161 can be radiated into the cavity 115, providing a good sound radiation passage between the rear side of the diaphragm 1161 and the cavity 115. To ensure acoustic performance, the volume of the rear cavity can be changed by adjusting the length of the straight side C1C2, thereby adjusting the size of the included angle α, and further by changing the area of ​​triangle C1C2C3 to adjust the volume of cavity 115. In some embodiments, due to limitations of the sound passage holes, the length of the straight side C2C3 is 0.67 mm or more. In some embodiments, the length of the straight side C2C3 may be 0.7 mm. In some embodiments, since there is a range limit on the value of the included angle α, there is also a range limit on the value of the volume V of cavity 115.

[0161] Figure 20C shows the frequency response curves of rear cavities corresponding to different sizes of included angle α in some embodiments of this specification. As shown in Figure 20C, when the length of the straight side BC is reduced and the included angle α is reduced from 67.6° to 45°, the volume V of the rear cavity decreases, and the corresponding acoustic capacitance Ca of the rear cavity becomes 7 × 10⁻⁶. -12 m 3 / Pa to 2.88 × 10 -12 m 3 The capacitance decreases to / Pa, but the resonant frequency of the rear cavity increases from approximately 4.5kHz to approximately 6kHz. When the length of the straight side BC is increased and the included angle α is increased from 67.6° to 79.11°, the volume V of the rear cavity increases, and the corresponding acoustic capacitance Ca of the rear cavity becomes 7 × 10⁻⁶.-12 m 3 / Pa to 15×10 -12 m 3 The impedance increases to / Pa, but the resonant frequency of the rear cavity decreases from approximately 4.5kHz to approximately 3kHz. Note that the 7×10 shown in Figure 20C -12 m 3 / Pa, 15×10 -12 m 3 Parameters such as / Pa represent only the theoretical acoustic capacitance value corresponding to the volume of the rear cavity, and there may be discrepancies with the actual data.

[0162] In some embodiments, the range of the value of the angle α in the cavity 115 may be 45° to 79.11°. In some embodiments, the range of the value of the angle α in the cavity 115 may be 60° to 70°. In some embodiments, the value of the angle α in the cavity 115 may be 67.6°. In some embodiments, the range of the value of the angle α in the cavity 115 may be 67° to 68°.

[0163] Figure 21 is an illustrative internal diagram of a transducer according to some embodiments of the present application.

[0164] As shown in Figure 21, the housing 111 houses the transducer 116, which includes a diaphragm 1161, a voice coil 1162, a frame 1163, and a magnetic circuit assembly 1164. The frame 1163 is positioned to surround the diaphragm 1161, the voice coil 1162, and the magnetic circuit assembly 1164 and is used to provide a mounting and fixing platform. The transducer 116 can be connected to the housing 111 via the frame 1163. The diaphragm 1161 covers the voice coil 1162 and the magnetic circuit assembly 1164 in the Z direction. The voice coil 1162 is inserted into the magnetic circuit assembly 1164 and connected to the diaphragm 1161. The magnetic field generated after the voice coil 1162 is energized interacts with the magnetic field formed by the magnetic circuit assembly 1164 to drive the diaphragm 1161 and generate mechanical vibrations, which further generate sound through propagation in a medium such as air. The sound is output through the sound outlet 112.

[0165] In some embodiments, the magnetic circuit assembly 1164 includes a flux conduction plate 11641, a magnet 11642, and a housing member 11643, wherein the flux conduction plate 11641 and the magnet 11642 are connected to each other, the side of the magnet 11642 away from the flux conduction plate 11641 is attached to the bottom wall of the housing member 11643, and there is a gap between the circumferential side of the magnet 11642 and the inner circumferential side wall of the housing member 11643. In some embodiments, the outer circumferential side wall of the housing member 11643 is connected to and fixed to a frame 1163. In some embodiments, both the housing member 11643 and the flux conduction plate 11641 may be made of a permeable material (e.g., iron).

[0166] In some embodiments, the circumferential side of the vibrating membrane 1161 may be connected to the frame 1163 via a retaining ring 1155. In some embodiments, the material of the retaining ring 1165 may include stainless steel or other metal materials to suit the manufacturing process of the vibrating membrane 1161.

[0167] As shown in Figures 20A and 21, in some embodiments, a larger projected area of ​​the diaphragm 1161 along the Z direction is preferable to improve the acoustic output (especially low-frequency output) effect of the sound generating unit 11 and to improve the ability of the diaphragm 1161 to push air. However, if the area of ​​the diaphragm 1161 is too large, the dimensions of the transducer 116 become too large, which makes the housing 111 excessively large and prone to collision friction between the housing 111 and the auricle, affecting the wearing comfort of the sound generating unit 11. Therefore, the dimensions of the housing 111 need to be designed accordingly. For example, the minor axis dimension (also called the width dimension) of the housing 111 in the Y direction can be determined based on the dimension along the Y direction of the concha (e.g., 17 mm), and the major axis dimension (also called the length dimension) of the housing 111 in the X direction (e.g., 21.49 mm) can be determined based on wearing comfort by selecting an appropriate length-to-short ratio (i.e., the ratio of the dimension of the housing 111 in the X direction to the dimension in the Y direction), thereby matching the dimension along the X direction of the concha.

[0168] In some embodiments, the dimensions of the housing 111 can be within a predetermined range to improve the acoustic performance of the earphones by facilitating wear for most users (for example, so that the sound generating unit 11 can be inserted into the concha or contact the antihelix region when most users wear the open-type earphones 10), and by forming a cavity structure with high acoustic effect, for example, by forming a first leakage structure UC and a second leakage structure LC between the housing and the user's ear when the open-type earphones 10 are worn. In some embodiments, the width dimension of the housing 111 along the Y direction may be in the range of 11 mm to 16 mm, based on the range of the width dimension along the Y direction of the concha. In some embodiments, the width dimension of the housing 111 along the Y direction may be 11 mm to 15 mm. In some embodiments, the width dimension of the housing 111 along the Y direction may be 14 mm to 15 mm. In some embodiments, the ratio of the dimension of the housing 111 in the X direction to the dimension in the Y direction may be 1.2 to 5. In some embodiments, the ratio of the X-direction dimension to the Y-direction dimension of the housing 111 may be 1.4 to 4. In some embodiments, the ratio of the X-direction dimension to the Y-direction dimension of the housing 111 may be 1.5 to 2. In some embodiments, the length dimension of the housing 111 along the X-direction may be in the range of 15 mm to 30 mm. In some embodiments, the length dimension of the housing 111 along the X-direction may be 16 mm to 28 mm. In some embodiments, the length dimension of the housing 111 along the X-direction may be 19 mm to 24 mm. In some embodiments, in order to avoid the volume of the housing 111 being too large and affecting the wearing comfort of the open-type earphone 10, the thickness dimension of the housing 111 along the Z-direction may be in the range of 5 mm to 20 mm. In some embodiments, the thickness dimension of the housing 111 along the Z-direction may be 5.1 mm to 18 mm. In some embodiments, the thickness dimension of the housing 111 along the Z-direction may be 6 mm to 15 mm. In some embodiments, the thickness dimension of the housing 111 along the Z direction may be 7 mm to 10 mm.In some embodiments, the area of ​​the inner surface IS of the housing 111 (equal to the product of the length dimension and width dimension of the housing 111 if the inner surface IS is rectangular) is 90 mm. 2 ~560mm 2 This may also be the case. In some embodiments, the area of ​​the inner surface IS can be considered to approximate the projected area of ​​the vibrating membrane 1161 along the Z direction. For example, the area of ​​the inner surface IS differs by 10% from the projected area of ​​the vibrating membrane 1161 along the Z direction. In some embodiments, the area of ​​the inner surface IS is 150 mm 2 ~360mm 2 This may also be the case. In some embodiments, the area of ​​the inner surface IS is 160 mm². 2 ~240mm 2 This may also be the case. In some embodiments, the area of ​​the inner surface IS is 180 mm². 2 ~200mm 2 This may also be the case. Based on the principles described in Figures 10 to 13, the earphones may be attached in the manner shown in Figure 14, and the dimensions of the open-type earphones 10 may be smaller than those of conventional open-type earphones, provided that the dimensions of the open-type earphones 10 satisfy the comfort of wearing them, and their acoustic performance is superior to that of conventional open-type earphones, that is, they achieve equivalent superior acoustic performance.

[0169] In some embodiments, the volume V of the rear cavity needs to be within an appropriate range of values ​​in order to increase the resonant frequency of the rear cavity and for the rear cavity to have a large acoustic capacitance Ca. In some embodiments, the distance from the center O1 of the first depressurization hole 1131 to the bottom surface of the magnetic circuit assembly 1164 can be rationally designed to appropriately set the range of values ​​for the rear cavity volume. As shown in Figures 20A and 21, when the thickness of the acoustic generating section 11 in the Z direction is constant, the smaller the distance along the Z direction from the center O1 of the first depressurization hole 1131 to the bottom surface of the magnetic circuit assembly 1164, the larger the volume of the rear cavity may be. In this case, as can be seen from equation (3) above, the acoustic capacitance Ca of the rear cavity increases, but the corresponding resonant frequency of the rear cavity decreases. In order to ensure that the sound generation efficiency of the sound generating unit 11 is sufficiently high, the resonant frequency of the rear cavity is within an appropriate frequency range (e.g., 2000Hz to 6000Hz), and the user is sufficiently comfortable to wear, the range of distance d5 along the Z direction from the center O1 of the first depressurization hole 1131 to the bottom surface of the magnetic circuit assembly 1164 (i.e., the side of the housing member 11643 that moves away from the sound emission hole 112 along the Z direction) is 1.31mm to 1.98mm. In some embodiments, the range of distance d5 along the Z direction from the center O1 of the first depressurization hole 1131 to the bottom surface of the magnetic circuit assembly 1164 is 1.31mm to 1.98mm. In some embodiments, the range of distance d5 along the Z direction from the center O1 of the first depressurization hole 1131 to the bottom surface of the magnetic circuit assembly 1164 is 1.41mm to 1.88mm. In some embodiments, the distance d5 along the Z-direction from the center O1 of the first pressure relief hole 1131 to the bottom surface of the magnetic circuit assembly 1164 ranges from 1.51 mm to 1.78 mm. In some embodiments, the distance d5 along the Z-direction from the center O1 of the first pressure relief hole 1131 to the bottom surface of the magnetic circuit assembly 1164 ranges from 1.56 mm to 1.72 mm. Similarly, in some embodiments, the distance d6 along the Z-direction from the center O2 of the second pressure relief hole 1132 to the bottom surface of the magnetic circuit assembly 1164 ranges from 1.31 mm to 1.98 mm.In some embodiments, the range of distance d6 along the Z-direction from the center O2 of the second pressure relief hole 1132 to the bottom surface of the magnetic circuit assembly 1164 is 1.41 mm to 1.88 mm. In some embodiments, the range of distance d6 along the Z-direction from the center O2 of the second pressure relief hole 1132 to the bottom surface of the magnetic circuit assembly 1164 is 1.51 mm to 1.78 mm. In some embodiments, the range of distance d6 along the Z-direction from the center O2 of the second pressure relief hole 1132 to the bottom surface of the magnetic circuit assembly 1164 is 1.56 mm to 1.72 mm.

[0170] In some embodiments, the dimensions of the sound generating unit 11 along the Y direction can be limited to match the dimensions of the concha cavities. In some embodiments, the dimensions of the sound generating unit 11 along the Y direction may be determined by the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 (for example, the back surface NN' perpendicular to the plane of the paper shown in Figure 21). In some embodiments, the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 (for example, the back surface NN' perpendicular to the plane of the paper shown in Figure 21) may be limited to facilitate design. In some embodiments, the range of the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 is 5.45 mm to 8.19 mm. In this application, the major axis center plane of the magnetic circuit assembly 1164 is a plane parallel to the lower surface LS of the sound generating unit 11 and passing through the centroid of the magnetic circuit assembly 1164. In other words, the major axis center plane of the magnetic circuit assembly 1164 may divide the magnetic circuit assembly 1164 into the same two parts along direction X. The distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 is the distance along the minor axis direction Y from the center O1 of the first decompression hole 1131 to the major axis center plane. In some embodiments, the range of the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 is 5.95 mm to 8.69 mm. In some embodiments, the range of the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 is 6.45 mm to 7.19 mm. In some embodiments, the range of the distance from the center O1 of the first decompression hole 1131 to the major axis center plane of the magnetic circuit assembly 1164 is 6.65 mm to 6.99 mm. Similarly, in some embodiments, the distance from the center O2 of the second pressure relief hole 1132 to the major axis center plane of the magnetic circuit assembly 1164 is in the range of 5.46 mm to 8.20 mm. In some embodiments, the distance from the center O2 of the second pressure relief hole 1132 to the major axis center plane of the magnetic circuit assembly 1164 is in the range of 5.96 mm to 8.70 mm.In some embodiments, the distance from the center O2 of the second pressure relief hole 1132 to the major axis center plane of the magnetic circuit assembly 1164 is in the range of 6.46 mm to 7.20 mm. In some embodiments, the distance from the center O2 of the second pressure relief hole 1132 to the major axis center plane of the magnetic circuit assembly 1164 is in the range of 6.66 mm to 7.00 mm.

[0171] In some embodiments, because pressure relief holes 113 (e.g., a first pressure relief hole 1131 and a second pressure relief hole 1132) are present, the air pressure in the rear cavity 115 near the pressure relief holes 113 is close to the external air pressure, and the air pressure in the rear cavity 115 is higher than the external air pressure. Because the frame 1163 is provided with sound-conducting holes (not shown) that connect the rear side of the vibrating membrane 1161 to the cavity 115, the sound-conducting holes in the frame may be asymmetrically positioned to better balance the airflow in order to balance the air pressure between the rear side of the vibrating membrane 1161 and the cavity 115. Specifically, because the air pressure is relatively high at positions far from the first pressure relief hole 1131 and / or the second pressure relief hole 1132, the dimensions of the sound-conducting holes may be large, and because the air pressure is low at positions close to the first pressure relief hole 1131 and / or the second pressure relief hole 1132, the dimensions of the sound-conducting holes may be small. In some embodiments, the low-frequency vibrations of the open-type earphone 10 can be further stabilized by adjusting the dimensions (e.g., the size of the cross-sectional area) of the first depressurization hole 1131, the second depressurization hole 1132, and / or the sound-permeable hole. In some embodiments, the first depressurization hole 1131 and the second depressurization hole 1132 can be offset in the X direction to further stabilize the vibration of the diaphragm by further stabilizing the air pressure in the rear cavity. In this case, the projections of the first depressurization hole 1131 and the second depressurization hole 1132 onto the longitudinal center plane are either partially overlapping or not overlapping. In some embodiments, the overlapping area of ​​the projections of the first depressurization hole 1131 and the second depressurization hole 1132 on the longitudinal center plane is 10.77 mm². 2 The following applies: In some embodiments, the overlapping area of ​​the projections of the first decompression hole 1131 and the second decompression hole 1132 in the longitudinal central plane is 6.77 mm². 2The following applies: In some embodiments, the overlapping area of ​​the projections of the first decompression hole 1131 and the second decompression hole 1132 in the longitudinal central plane is 4.77 mm². 2 The following applies: In some embodiments, the overlapping area of ​​the projections of the first decompression hole 1131 and the second decompression hole 1132 in the longitudinal central plane is 2.77 mm². 2 The following applies:

[0172] Figure 22 is a schematic diagram of the housing of an open-type earphone along the Z-direction on the plane in which the bottom surface of the magnetic circuit assembly is located.

[0173] In some embodiments, the projection point of the center O1 of the first decompression hole 1131 along the Z direction on the plane where the bottom surface of the magnetic circuit assembly 1164 is located is O1'', and the projection point of the center O2 of the second decompression hole 1132 along the Z direction on the plane where the bottom surface of the magnetic circuit assembly 1164 is located is O2''. In order to offset the first decompression hole 1131 and the second decompression hole 1132 in the X direction, the length range of the connecting wires O1''O2'' can be made larger than the minor axis dimension of the sound generating unit 11. In some embodiments, the length range of the connecting wires O1''O2'' is 11 mm to 16 mm. In some embodiments, the length range of the connecting wires O1''O2'' is 8.51 mm to 15.81 mm. In some embodiments, the length range of the connecting wires O1''O2'' is 10.51 mm to 15.81 mm. In some embodiments, the length range of the connecting wires O1''O2'' is 11.51 mm to 14.81 mm. In some embodiments, the length range of the connecting wires O1''O2'' is 12.51 mm to 13.81 mm. In some embodiments, the ratio of the length of the connecting wires O1''O2'' to the width dimension of the sound generating unit 11 may be 1 to 1.88.

[0174] In some embodiments, the degree of displacement in the X direction between the first depressurization hole 1131 and the second depressurization hole 1132 cannot be too large. If the degree of displacement is too large, the first depressurization hole 1131 and the second depressurization hole 1132 tend to come close to the free end FE or the connecting end CE in the X direction, and as a result, when the open-type earphone 10 is worn, the first depressurization hole 1131 and / or the second depressurization hole 1132 are shielded by the structure of the ear (e.g., the side wall of the concha cavity, the tragus, etc.). In some embodiments, the degree of displacement in the X direction between the first depressurization hole 1131 and the second depressurization hole 1132 may be related to the angle β between the connecting line O1''O2'' and the short axis direction Y. In some embodiments, the angular range of the angle β may be 12.85° to 23.88°. In some embodiments, the angular range of the angle β may be 14.85° to 21.88°. In some embodiments, the angular range of the included angle β may be 16.85° to 19.88°. In some embodiments, the angular range of the included angle β may be 18.85° to 29.88°.

[0175] The above description of the open-type earphone 10 is for illustrative purposes only and is not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications based on the description of this application. For example, if only one depressurization hole is installed in the sound generating unit 11, the depressurization hole may be either the first depressurization hole 1131 or the second depressurization hole 1132. For example, the depressurization hole may be the first depressurization hole 1131, that is, it may be installed on the upper side surface US. The distance from the center of the depressurization hole to the inner side surface IS may be in the range of 4.24 mm to 6.38 mm, and the distance from the center of the depressurization hole to the rear side surface RS may be in the range of 10.44 mm to 15.68 mm. These changes and modifications are still within the scope of protection of this application.

[0176] Having explained the basic concepts above, it will be clear to those skilled in the art that the above detailed disclosures are merely illustrative and do not limit the present application. Although not explicitly stated herein, those skilled in the art can make various changes, improvements, and modifications to the present application. These changes, improvements, and modifications are intended to be suggested by the present application and remain within the spirit and scope of the exemplary embodiments of the present application. [Explanation of symbols]

[0177] 10 Open-type earphones 11. Sound generation unit 12 Ear hooks 100 ears 101 External auditory canal 102 Concha cavity 103 Concha navicular 104 Triangular fossa 105 Antihelix 106 Scaphoid fossa 107 Helix 108 Earlobe 109 Tragus 111 Housing 112 Sound emission hole 113 Depressurization port 114 Front Cavity 115 Cavity 116 Transducer 117 Bracket 118 Acoustic Resistance Mesh 1161 Vibrating membrane 1164 Magnetic Circuit Assembly 1131 First depressurization hole 1132 Second depressurization port 1071 Helical foot

Claims

1. A sound generating unit including a transducer with a diaphragm and a housing that houses the transducer, When worn, the device includes an ear hook, the first portion of which is placed between the user's auricle and head, and the second portion which extends from the side of the auricle away from the head and is connected to the sound generating unit, thereby fixing the sound generating unit in a position near the ear canal so as not to block the ear canal. A sound-emitting hole is formed on the inner surface of the housing facing the auricle, for guiding sound generated in front of the diaphragm out of the housing and transmitting it to the ear canal; at least two decompression holes are formed on at least one of the upper, lower, or outer surfaces of the housing, and the at least two decompression holes include a first decompression hole and a second decompression hole, with the distance between the center of the first decompression hole and the center of the second decompression hole being 13.0 mm to 15.2 mm. The first pressure relief hole is formed on the upper surface of the housing, The second pressure relief hole is formed on the lower surface of the housing, When worn, the housing is inserted at least partially into the concha of the ear. An open-type earphone in which the distance from the center of the second pressure relief hole to the rear side surface of the housing is greater than the distance from the center of the first pressure relief hole to the rear side surface.

2. The open-type earphone according to claim 1, wherein the distance from the center of the sound-emitting hole to the perpendicular bisector plane of the connection line between the center of the first decompression hole and the center of the second decompression hole is 0 mm to 2 mm.

3. The open-type earphone according to claim 1, wherein the distance from the center of the first pressure relief hole to the inner surface of the housing toward the auricle is in the range of 4.24 mm to 6.38 mm.

4. The open-type earphone according to claim 1, wherein the area of ​​the second pressure relief hole is smaller than the area of ​​the first pressure relief hole.

5. The area of ​​the first pressure relief hole is 3.78 mm². ２ ~22.07mm ２ The area of ​​the second pressure relief hole is 2.78 mm². ２ ~16.07mm ２ The open-type earphone according to claim 4.

6. The open-type earphone according to claim 1, wherein the distance range from the projection point of the center of the first pressure relief hole onto the sagittal plane to the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane is 2 mm or less.

7. The open-type earphone according to claim 6, wherein the distance from the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane to the projection point of the center of the ear canal opening onto the sagittal plane is in the range of 12 mm to 18 mm.

8. The open-type earphone according to claim 6, wherein the distance from the projection point of the center of the first decompression hole onto the sagittal plane to the projection point of the center of the ear canal opening onto the sagittal plane is in the range of 12 mm to 18 mm.

9. The open-type earphone according to claim 6, wherein the range of distance from the projection point of the center of the second decompression hole onto the sagittal plane to the projection point of the center of the ear canal opening onto the sagittal plane is 6.88 mm to 10.32 mm.

10. The open-type earphone according to claim 6, wherein the distance range from the projection point of the center of the second pressure relief hole onto the sagittal plane to the projection point of the midpoint of the upper boundary of the inner surface onto the sagittal plane is 14.4 mm to 21.6 mm.

11. The open-type earphone according to claim 1, wherein the distance range from the projection point of the center of the first decompression hole onto the sagittal plane to the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane is 13.76 mm to 20.64 mm.

12. The open-type earphone according to claim 11, wherein the range of distance from the projection point of the center of the second pressure relief hole onto the sagittal plane to the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane is 8.16 mm to 12.24 mm.

13. The open-type earphone according to claim 12, wherein the distance range from the projection point of the 1 / 3 point of the lower boundary of the inner surface onto the sagittal plane to the projection point of the center of the ear canal opening onto the sagittal plane is 1.76 mm to 2.64 mm.

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